Microsoft Virtual PC 2004 - NOW FREE
In a surprising move Microsoft have made Virtual PC 2004 (a Windows only version) available as a free download. It's downloading as I type, but I don't think it will run the Vista Beta I've got waiting to be installed. This is a really useful piece of software, especially for testing set-ups/beta software, and I intend to use it to run a clean Windows OS with the Office 2007 Beta installed later today! Excellent; now, why would they do this? And when is the Mac version going to be free?
Edit: for the answer to the first question see the Virtual PC Guy's blog post.