I've been playing around with Flex 2 for some time at work. One of the neat things that Actionscript 3 adds is native regular expressions. As part of an ongoing effort to share knowledge I volunteered to give an informal talk about regular expressions. To help with the talk I created this visual regular expression viewer. It helps show you what matched along with any groupings and other standard stuff. Additionally it can also perform a regular expression replace operation or a simple split operation.
You will need the Flash 9 in order to run the application.
If you find any bugs, have comments, etc. please leave me a comment.