The FLEXifier allows you to experience Flex 2 for yourself, without needing to download or install anything. Of course, you really should download Flex Builder 2 to truly get a feel for Flex, especially if you want to save your project :). However, if you’re really cheap or lazy, you may use The FLEXifier to compile and run MXML and ActionScript code from anywhere, with an internet connection. Simply enter your code, and click the Try It! button. Use your own code, or use canned code that you can tweak and modify as you see fit. Enjoy! http://try.flex.org/

Oh yeah, almost forgot my mandatory shout out to Tim, another developer cohort.