If you want to run Windows on your Mac, you have had up until now four main choices, Boot Camp, Parallels, VMware and Crossover.
Now there is a fifth (free) choice, Virtualbox from Sun.
VirtualBox is a family of powerful x86 virtualization products for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers, it is also the only professional solution that is freely available as Open Source Software under the terms of the GNU General Public License (GPL). See “About VirtualBox” for an introduction.
Presently, VirtualBox runs on Windows, Linux, Macintosh and OpenSolaris hosts and supports a large number of guest operating systems including but not limited to Windows (NT 4.0, 2000, XP, Server 2003, Vista), DOS/Windows 3.x, Linux (2.4 and 2.6), and OpenBSD.
I have downloaded it, but not yet installed it or tried to run Windows on it. Certainly looks like it could be useful for a whole range of virtualization solutions.
A lot of people say I can’t buy a Mac as I need to run Windows, well it’s never been easier to run Windows on a Mac these days, and with virtualization you can run both OS X and Windows XP (and Ubuntu. Vista, even Windows 3.1!) on a single computer.