Geeks are Sexy have a useful post on Installing WordPress Locally Under Windows XP for those of you who might like to do so (and those who have a PC). As Kiltak comments in the posts, having a local version can be ‘useful because it lets you fool around with themes and plugins to your heart’s desire without having to risk breaking your live blog.’
How to Install WordPress Locally on a PC
Problogger.net runs on the Genesis Framework
The Genesis Framework empowers you to quickly and easily build incredible websites with WordPress. Genesis provides the secure and search-engine-optimized foundation that takes WordPress to places you never thought it could go.