If you're going to install the 10.7 preview on a separate hard drive or partition, it's definitely worth knowing about Buttered Cat Software's QuickBoot, which allows you to change startup disks and reboot from your menu bar.
I'm a programmer, author, and one of the founders of MartianCraft, a software development shop doing both contract and in-house software development.
My iPhone books (both written with Dave Mark) are published by Apress. My first book, Beginning iPhone Development (currently in its 6th edition) is the all-time best-selling book on learning to program the iPhone and iPad.
I also sculpt and take pictures when I need to engage the other side of my brain a little more.