I’ve long been a fan of running the prereleases of microsoft’s OSs, from an Alpha of NT 5.0 that refused to change VGA drivers up to Longhorn. If nothing else, it’s a useful way of keeping up to date with all the ‘innovations’ that Microsoft jam into their software to keep hardware manufacturers in business.
Windows 7 is actually looking like it will be the OS that Vista was supposed to be, as in useful without more than 2 Gb of RAM. I’ve run it up in a VM and it took all of 300Mb on idle. which was nice.
So if you’d like the chance to try it out until the summer, not just the 30 days before Activation makes it fail, http://blog.hznet.nl/2009/01/10/how-to-receive-a-valid-windows-7-key is probably the place to start.
It’s a shame that there isn’t a legal method of obtaining OS X though.. 🙁