Postpostmodern » A Smarter MAMP
http://postpostmodern.com/instructional/a-smarter-mamp/
How to Set Up a Killer WordPress Testing Environment Locally - Nettuts+
http://net.tutsplus.com/tutorials/wordpress/how-to-set-up-a-killer-wordpress-testing-environment-locally/

net.tutsplus.com: set up wordpress testing environment locally

If you're a heavy WordPress developer like me, you might find that you need to create a new installation for each site that requires a strange structure or specific posts, instead of using your uniform local test WordPress installation. Cue WordPress Mu. WordPress Multi User is a platform created by the geniuses at Automattic that is basically a WordPress installation that allows multiple blogs to run using the same software.

How to Set Up a Killer WordPress Testing Environment Locally

Nice post on how to install a local server for testing purposes.

http://localhost/wp/