Slowly Dying Mac

I've got a PowerBook G4 with tons of processing power and OS X 10.3.9. It's slowing been winding down into the unknown oblivion of computer drudgery. In other words, it's inexplicably become as slow as dirt. Everything takes for every, apps sometimes don't open on the first try, and Microsoft Word freezes all the time (as opposed to only doing so once in a while but still more than all other programs combined).

I was going to clean install everything, maybe even erase the entire disk, now that it's summer break, but I'm in China (until this weekend, thankfully) and I've got no reliable internet connection to download all the updates and such that I'll need. Also, I kind of just want to pack this all into one punch and do it all as I upgrade to Tiger, which should be sitting at home for me when I get there.

It is getting intolerable. The entire thing is sluggish. It takes forever to open a program, and even switching between calendar views, mail folders, and such can be a pain in the ass. This has meant that recently my Mac has been about as annoying as the Windows computer I use at work. I can't wait to finally fix this problem.