I can't believe there isn't an Ubuntu 9.10 Karmic Koala thread yet.
I've been experimenting with the minimal install suggested at
http://www.psychocats.net/ubuntu/minimal for karmic and my pc really flies (Dell Dimension 3000; 3 GHz; 1 GB RAM).

Frankly, I triple boot this machine (WinXP, CrunchBang & Ubuntu 9.10). For ordinary surfing--read: security--you can't beat linux; OTOH, some online video really works better from a WinXP platform (e.g., divx). Moreover, certain applications like BitWare, Spider, etc., keep me booting up WinXP everyday as well.