Great thread... 12 years and still going. But I have to echo the OP that OSX 10.4's memory management is crap. It works fine most of the time, but periodically fails catastrophically. I still have a 1.8 GHz G4 with 2 GB RAM, and I keep a 300 MB RAMdisk active at all times, e.g. for temp stuff, downloads, unzipping, etc. But occasionally, OSX will swap part or all of my RAMdisk to the hard drive--even though there are many hundreds of MB of inactive RAM. This should NEVER, EVER happen under any circumstances (i.e. a RAMdisk getting swapped to VM). Hence, OSX is only marginally functional crap.
Btw macrumors, please revert your javascript. TenFourFox (a Firefox port for OSX 10.4/10.5) grabbed 600 MB just to load your webpage. Nor did the captcha ever appear, etc. Nobody's impressed by stuff like that. (and the same thing happened on my Core i5 running Win7) Thanx.