VMWare
VMware kicks ass. In a nutshell, it lets you emulate one or many simultaneous “virtual machines”, allowing you to host literally any OS on a windows or linux box.
For me, it was a question of Linux on Windows, or Windows on Linux. I already run WinXP, so using that as the base for Linux seemed natural. However, I’m fairly good with linux, and I would use it as my OS if I could get it to work with my specialized windows only hardware (Sigma, you bastards), and I could play games.
Ah, the games. Windows on Linux with vmware still doesn’t do DirectX, and it doesn’t look like it will anytime soon. For now, the best option appears to be transgaming.com.
So, it took about 40 minutes to do a full Redhat 7.3 ftp install, and it got up and running painlessly. No bootdisks; vmware can mount disk images directly. No CDs; ftp install is gangbusters over OC3.
VMware does network bridging to give linux and windows separate IPs. It has a special X11 server for accelerated 2D graphics under windows. In general, it’s just pretty damn cool.