I've been playing around with VMware since about 2000, but I've never had a computer powerful enough to really run it. Yesterday, I bought another 1gig stick of RAM for my MacBook, which puts me at 2gigs. That's not a heck of a lot, but it's enough.
I now have OS X, Ubuntu, and NetBSD running full screen on different OS X Spaces. I setup VMware Fusion to allow Ubuntu to use both CPUs and 1gig of RAM, whereas I only allocated 1 CPU and 256mb of RAM for NetBSD. OS X does fine with whatever the other two don't use. Ubuntu now has enough horsepower that I can even play the video game I wrote at full speed.
With a simple hot key, I can be in OS X, Ubuntu, or NetBSD. Even better: I can shut the lid of my laptop, and all three suspend without crashing. They all share my Mac's wireless connection, which tends to be pretty stable. If something is giving me a hard time installing under MacPorts, I can just install it on Ubuntu.
Being a minimalist, I only have one computer, so it's kind of hard to play around with fringe OSs, which I used to love doing. That's about to change. Next up, MINIX 3 and pc-bsd!
Oh my gosh that's cool!!!