My main PC is a Toshiba Portege 3480CT (Pentium3 600) and it maxes out at 192 MB RAM.

I just set up on the fly RAM/swap compression with zram yesterday (had to upgrade to Debian Wheezy) and am loving the increase in memory capacity!

I use ScrotWM, Iceweasel (Firefox 7), Alpine and a fair number of text-based apps. And I'm about as productive as I've ever been on any previous computer.