I've been on a flagging binge, and was batting 1000 when I hit this question
https://serverfault.com/questions/2423/what-are-some-must-have-iphone-itouch-apps-for-it-people

That wasn't accepted, but https://serverfault.com/questions/2423/what-are-some-must-have-iphone-itouch-apps-for-it-people was deemed as an acceptable flag.

What's the difference?