For anything programming related, HTML, Obj-C dabbling, scripts, I use TextWrangler. I'm not going pro any time soon so the upgrade to BBEdit is not worth it for me. In the CLI I use vi or nano, depends if someone's over my shoulder or not. For word processing I've been using NeoOffice/J, but the nag for updates has been bugging the HELL out of me lately. I might run back to OpenOffice.org or perhaps try out the trial version of Pages that came with my Mini.

I use Tinderbox for making notes, and for the first draft of anything that might be hypertextual -- or that's likely to need structural editing. Being able to move things around in both outlines AND maps can't be beat, and Tinderbox's export facilities make it easy to move to presentation software.

For small talks, I present in Tinderbox; for large audiences, I move to Keynote.

For papers, where styles tend to be defined by Word templates, I export to HTML and import the first draft in Word. Apply the appropriate style template, revise to length, and all is well. I'm doing more writing in Word this week, and though much (and sometimes justly) maligned, it's not as bad as many think.

For diagrams, I'm using Graffle. For images, Painter and Fireworks.

Microsoft Word works for me. I wish I had an alternative but I can't risk any incompatibility with clients - being on a Mac is risky enough. I've tried several different tools to help the writing process, mostly to organize thoughts, record useful links, rough out ideas, and to track different projects. At the moment I'm having some success with VooDooPad from Flying Meat (http://flyingmeat.com/). It's fast and simple - two big prerequisites for me.

I also love Flying Meat's FlySketch. If a client wants a quick graphic in a piece I no longer have create things from scratch. If I can find something that fits the bill in a PPT, PDF, or web page I grab it with FlySketch and save it as a jpeg. If it needs modifying I do that with Intaglio from PurgatoryDesigns (http://www.purgatorydesign.com/Intaglio/) where I also create any from-scratch graphics I need. My clients inevitably use a graphic designer to do document formating and illustration work but the FLySketch graphics serve as useful placeholders.

I've also been using TextLightning from MetaObject (http://www.metaobject.com/Home.html) to cull copy from PDF files into a text file. Useful for existing blocks of copy that have to be included in a piece. I have to say I don't really like this product much. It tends to smush a lot of words together and does dumb things - like transcibes all manner of incidental text making the output document a nightmare to go through. I'm not even sure it's better than cut and paste from a PDF but I still use it when I have to.

For general small business office utilities I use MaxEmail (http://www.maxemail.com/) for fax services. When I'm emailed or faxed a contract from a client I open the PDF file with PDFPen from SmileOnMyMac (http://www.smileonmymac.com/PDFpen/index.html) and insert a jpeg signature before faxing back through MaxEmail.

I use LyX for formal papers and engineering documents because it does all the styling and layout 100% automatically for me and generates fantastic PDF. LyX is a TeX front end, but you can install teTeX and LyX both from packages and you don't have to configure a thing, so it sounds more unfriendly than it is. Those are the only "documents" I produce in the traditional sense on a regular basis. When I need the occasional prettier document, I use Pages.

I find "word processors" to be huge, slow, painful, and inept at helping me do anything. I spend the vast majority of my time with one fixing its broken behaviors and very little time writing. With LyX, I spend 2 seconds once in a while telling it I'm beginning a new section or sub-section or chapter or list or whatever, that's it.

Otherwise, I use a handful of what I'd call utility apps: OmniOutliner for lists and outlines and notes and lists with notes (I love it); VoodooPad and/or Yojimbo for "writing things down" (mostly Yojimbo now); ecto for blog posts.

TextMate for research papers; Pages for letters (business or personal). I'm surprised Rob talked about Nisus Writer Express but didn't even mention Pages, given that he mainly seems to be interested in Word compatibility. I've found that Pages does a much better job of importing Word documents than NWE. (I own both.)

TextWrangler is fast becoming a favorite for its ability to wrestle plain text into place. My most common uses: set a soft wrap and later convert it to hard wrap, straighten quotes, set selections to all caps, zap gremlins, normalize line endings and find/replace with regex. Being able to use its FTP/SFTP capability is nice though mostly I use Dreamweaver, with Dreamweaver based projects, and Cyberduck, for everything else, for that. Cyberduck actually has a very useful integration with Smultron that allows you to rapidly edit online documents right from within the FTP program.

For editing programming related items, conf files, etc. I often use Smultron (or nano or vim if I am working in Terminal). Most of my original programming work is PHP/MySQL related and for that I often use Dreamweaver (super fast application development plus good project management tools) and Zend Studio (debugging and code analysis). I also try to start using Eclipse every couple of months but it never sticks. Dreamweaver also gets most of my HTML and CSS work, BTW.

For documents, which I usually am editing for other people, I use Microsoft Word (OpenOffice cannot match Word's commenting ability... not anywhere near as useful or visually pleasing plus the people I am editing all use Word and this makes compatibility a non-issue. In the past, I tried OpenOffice and some people complained of strange results when viewing in Word).
All of my organizing is done via Dreamweaver's project management capabilities or good old Finder. I don't use Outliners as they just don't work for me

I'm a technical writer, FrameMaker has been my primary writing tool at work for the last 8 years or so. Unfortunately, Adoobie [sic] never updated it to work with OSX, then dropped Mac support for it altogether. I haven't used Word since version 7 (aka Word 95), and I'm convinced that later versions are a step backward in functionality (numbering nightmares, etc.).

So I'm going back to my gnarly (but much-improved) roots: Vim for editing, groff for formatting. If I need to share source with the unenlightened, I can format to HTML and they can open that in Word.

Anyone else willing to give this a shot should have a look at http://unixtext.org/

I use VoodooPad for all notes, planning and drafts, but tend to shift around for what app to use with the final product.

I'm a paralegal student in southern CA. I own Pages, NWE, and Word 2004. In a perfect world, I would use NWE for everything. The reality is, that for all of my classes there are course modules (containing sample complaints, client correspondence letters, intraoffice memoranda, etc.) that the students download from the web - and they're all in .doc format. In the legal profession, form is everything. I tried opening up the .doc files with NWE - no luck. It was slow, and it didn't translate properly. Next, I tried Pages - much, much better, but it still lagged on a trial brief that had a two-column format and a ton of HTML. So yeah......that blue 'W' now has its own special spot in my Dock.

I also tried NeoOffice/J, but in general found it to be too sluggish.

TextMate for both writing in LaTeX and programming code (Ruby, Python, ObjC, JavaScript/HTML/XML, etc.) - Hopefully a future release will offer a split screen option as well as a full screen option.
TeXShop for the rare occasion it comes in handy. Subversion for full revision storage and sync between multiple computers. OS X built in Dictionary/Thesaurus and Spellchecker plus Spotlight which works great with plain text like tex/latex files. Favorite font - Bitstream Vera Sans Mono a fixed width font that supports bold/italic/underline yet is still fixed width.

The learning curve of LaTeX is extensive but it is also extremely rewarding. If you touch type and what writer doesn't? Then you should seriously start messing around with LaTeX. It produces wonderfully formatted documents and the PDF abilities are awesome. I've seen entire presentations done in PDF with full navigation, layers, etc. It can be done, but it does take longer to setup a new layout in LaTeX. But then you don't have to think about layout once that part is complete. You can focus on the content instead. Instead of WYSIWYG it becomes WYSIWYN (What You See Is What You Need). LyX is a good front end to LaTeX that tries to display the results while you enter it. It's more of a compromise between editing LaTeX source by hand and WYSIWYG. Try LyX first to ween yourself off WYSIWYG then get into learning more about LaTeX.

I use Tinderbox for works-in-progress, then pour those contents into Word if that's what the final deliverable needs to be, or into BBedit if HTML is required.