Thanks for the reply, Derrick.
First let me explain how I see iPhoto and PSE (Photoshop Element) fit into my "world view" [grin] and then what I think my workflow will be.
"MY WORLD VIEW", or "WHAT IS iPHOTO'S ROLE"?:
1. iPhoto is a photo organizing app. Via the Media Browser in other apps (iMovie, iDVD, Keynote, Pages), I can access all my photos for use in DVD slideshows, movies, presentations, newsletters, etc.
2. There are 2 divisions in how I use photos: (a) photos that need to be as close to perfect as possible which is relatively rare (i.e., printing out an 8x10 for framing), and (b) "good enough" photos that will be reproduced at smaller sizes and/or resolutions but whose use is much more common (iDVD and iMovie images are only 640x480, and presentations and newsletters will never use the full 6 megapixels of my dSLR). The "a" images above will be printed directly from PSE using the original Raw file that is processed as a PSD (so as not to lose quality). The "b" images above can all be high resolution JPEGs of about 1-2 MB each, and get imported to iPhoto for organizing.
3. I need all the photos from a single year in a single iPhoto library, so that I can easily create end-of-year holiday cards, and "Best Of 2005" slideshows, for example. I don't want images from within one year broken up into separate libraries.
4. Limited HD space on my PowerBook. I also want to be able to back up my iPhoto libraries to a single DVD+R disc (since iPhoto doesn't support backing up across multiple pieces of media). So my library for an entire year must be 4.3 GB or less.
5. I take Raw photos for a reason--I want control over how they're converted to JPEG. iPhoto 5 doesn't give me that control, but PSE 3 does.
6. I will backup my Raw files ("negatives") separately from my iPhoto library. Raw files are like negatives, while iPhoto JPEGs are like printed photo albums (to compare to the pre-digital world).
For all the reasons stated above, I've decided to do this:
1. To keep all the pictures in a single year small enough to fit in a single iPhoto library that fits on a single DVD+R disc, I will *only* import JPEGs into iPhoto. I will not import Raw files.
2. I download the Raw files from my Pentax *ist DS into a directory structure on my external Firewire disk that stores 100 sequentially numbered Raw files in each directory. Since each Pentax Raw file is about 10 MB, I can put 400 Raw images on each DVD+R disc.
3. I use PSE's Adobe Raw Converter plugin to tweak each Raw file (the "auto" settings are a blessing, and it's great that I can override them if I want to--but I don't have to) and then export to a high quality, full resolution JPEG (about 1-2 MB each).
4. I import those JPEGs into iPhoto 5.
By doing it this way, I gain these benefits:
1. My Raw files ("negatives") are backed up separately from my JPEGs.
2. iPhoto library sizes are manageable (since there are no Raw files in them), and I can keep a whole year's worth of photos in a single iPhoto library that fits on a single DVD+R disc.
3. When I want a super-high-resolution, uncompressed image to print at 8x10 or 11x14, I go straight to the original Raw file and tweak it to a PSD file and print from there. This is fairly rare (I mean, how many photos can you have on the walls in your house?!) so the fact that the Raw files are not in iPhoto is not a problem. (I can find the JPEG easily in iPhoto, and then use the original file name to go back to my backed up Raw images and grab it from there. Very easy.)
4. When I want to use my photos in other projects where resolution or compression is not so critical (DVDs, movies, presentations, newsletters, etc.), I have a tweaked good-enough-quality JPEG in my iPhoto library so I can access it from the Media Browser in the iLife and iWork apps.
Whew, that was a long post! But, for my uses, this makes the most sense. It separates the uses of iPhoto from PSE, allows me access to medium quality or super-high-quality when I need it, keeps library size to a minimum, and makes everything easy to back up!
I'd appreciate other folks' comments on their workflows, or suggestions on how to improve mine. Thanks!