Someone brought me a ThinkPad R60; it has 1 GB of RAM, an Intel T1300 CPU, 5400rpm IDE HDD, and still has WinXP installed. I booted it up just for fun and… it's still impressive how lean XP was. Everything launches and reacts instantly, and the whole OS with a couple windows open fits in 210 MB of RAM. The largest process, the "Explorer" file manager, fits in 25 MB. Even as a Linux desktop user, I haven't often seen this level of scarce resources optimization lately.