(watch iframes Part 1 full screen)
(watch iframes Part 2 full screen)
There are other resources -
Unfortunately, Fan Page Engine has only released their iframe solution to existing customers.
Lujure has released an FBML to iframe converter, and it looks like any new custom tabs created there are already iframes… so that’s awesome news!
You could, of course, create new web pages anywhere (not just on WordPress) and install by creating a new application!
COOL TIP: You can change the name of tabs now (see screenshot)!