I know many people will complain that this is not a hint, but after I discontinued my MobileMe subscription, I never bothered trying to turn back on Find My [iDevice] because I assumed I couldn't use it anymore.
So this IS a hint for those users that don't keep up with Apple news and made the same assumption I did. For anyone who doesn't know, you can just go to add a MobileMe account on the iDevice and use your App Store username and password (i.e. your AppleID).
I know I would've been glad to see this before I found out about it.
[crarko adds: Once again, what may be common knowledge to some is news to other people, and we like to look out for everyone.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=2011010417525166