Get Lindows 4.0. If you don't use dialup, it will work with broadband and is a wonderful replacement for Windows 98. Its cheaper than even Windows XP!
A friend of mine got one of those Lindows PCs and we decided to blow Lindows away. Installed Red Hat 9 which came up and recognized all of the hardware. Then we installed Win2K Pro, which needed new drivers for the video, sound and modem card. Added a diskette drive and another 40GB IDE drive.
1.1 GHz. Duron with (kinda) state-of-the-art software for about $250.... can't beat that.