Digital Media Minute just posted a link to the Regular Expression Library which is a repository of Regular Expression expressions (currently with over 450 entries).
This is a useful resource if your are developing applications for Central, as Central has built in support for regular expressions. Of course, it is also useful if you are using one of the community developed Flash regular expression libraries.
You can view the website here.
You can find some more information on Regular Expressions in Central here and here.
Btw, we will be posting an extensive article on using Regular Expressions in Central on the DevNet center very soon.