i got one , i gotta warn you its not simple..
normally i just hand these things out , but this is a bit complicated.
heres an example
http://tools.webspacemania.com/pop/
beats firefox and ie7 with all the popup blockers you can throw at it
( both entrance and exits )
now keep in mind i put some work into this , the script is done in php so that google and other se's cant see the code. what it does is builds the js file "on-the-fly" based on what browser you are using. so if you looked at the javascript in firefox all you will see is the firefox code ( so its not just cut and paste code )
im a bit busy with some other stuff , i will try to contact those interested