Through my travels of the internets, I have encountered a great website for iPhone developers looking to have their applications beta tested by real people.  The website is called iBetaTest.com . 
Launching their site just yesterday, iBetaTest.com already boasts 135 registered testers and 44 registered developers!  Here is the skinny on how it works (per their website).

Beta testers and developers register for a free account
Beta testers log in and go into the Device Manager and add all of their devices
Developers can …