I did take my powerbook to the apple store on Wednesday. The diagnosis? A hard drive that's on the verge of collapse. I spent Wednesday night backing up files to DVDs (my most recent backup in Rochester is several months old, alas), and being grateful that I'd brought two computers with me.
The powerbook is still partially functional. I can run my browser and email programs, as well as iTunes and iPhoto, which meant I was able to backup everythign that mattered. But my aggregator (NetNewsWire) and blogging client (ecto) have already stopped working, and the email's starting to get a little flaky.
So while I'm here, I'll be working mostly with the TabletPC. I'll have our tech guys send my laptop in for repairs when I get home. (It has one other really odd problem; when I'm in an airplane, the E key doesn't work properly; I'm guessing this has to do with the effect of cabin pressurization, but I don't know if it's the keyboard or the logic board that's reacting.)
That's so great that you picked up on this before it died altogether - having a grace period to do backups is good.
Good luck on the repairs..
A few thoughts, if its under warranty Apple will replace it (if your machine isn't to dented/abused.
If it's not and you send it out, bigger faster hard drives are out these days so you might consider getting them to upgrade it.
The upgrade isn't hard to do (for the semi-geeky), a 100GB drive that's likely faster (5400RPM) than what you have is $199 these days and I'll list the URL for a super easy install manual. I just did my 12 inch PowerBook, which people say is difficult machine and it was a breeze (but the HD is really easy to get to compared to some parts). http://www.cdwg.com/shop/products/default.aspx?EDC=729369
These are the guys that offer the FREE step-by-step color instructions in PDF format. They even print you out a page with spots labeled so you can set the screws down in it's particular spot so that you find them when you are done. http://www.pbfixit.com/Guide/