If you’ve ever wondered how other people name their files, there’s a great thread all about it over at 43Folders.
Turns out people use all sorts of different systems, usually including some sort of date reference, or abbreviations for clients and projects.
I like many of the points made by nex, who remarks that good, modern desktop search has made filenaming less important:
Use a system that will work with your laziness, in spite of your laziness, something that doesn’t rely on you forcing yourself to play by tedious rules
I couldn’t agree with that more. Personally, I don’t bother with dates in filenames, since the Created and Modified dates created by OS X are enough. I make use of a handful of prefixes (“orb” for O’Reilly blog, “mu” for MacUser, and so on) but otherwise leave things as simple and as easy-to-remember as possible.


Of course, some apps don't retain those dates when exporting following processing (iPhoto for example), so I use yymmdd_#### religiously in that case to avoid namespace collision mostly and also retain dates.
join GAA today! (that's Group Against Acronyms, in case you didn't know)