This probably isn't as adaptable as vmware which bridges the network adapter, and can give decent performance, but there's no install using this method.
50MB for
Damn small linux image compressed
click the bat file, and boom - you're in linux running within your main os - QEMU is also used to run windows in linux, and there's an example running nested emulation. Pretty cool stuff if you want to try linux but you're afraid to even try the free vmware server.
Several os images for qemu are
here
