Craigslist Desktop Application was released by Cobalt Fire Software. This application solves all the unusable elements about Craigslist. CLDesktop improves the design of Craigslist and utilizes its search features better. You can save your searches and refer back to them.
Download CL Desktop
(Available for both Windows and Mac OS X)
http://www.cldesktop.com/
Grant Skinner created an amazing regular expressions tester which is available as a web application or as a desktop air application.
This application allows you to create regular expressions and then test them on the fly. I highly recommend downloading this application for testing your regular expressions. I used this to successfully debug some regex parsing errors taking an SVG into flex.