charging myth? Better to charge when drained? Or not?

[ipod]

I was wondering if it was bad to charge your phone when theres still a little bit of juice in it? Cause I heard that its better to charge when your phone is fully drained/dead. This true? Thanks all. Happy holiday!

[Spikefood]

I recharge every night regardless of how dead it is. I figure I've got a warranty so if the battery does go bad I can get my Iphone replaced.

[tupacinla]

its been said to do that once a month to revitalize the battery.

http://www.apple.com/batteries/iphone.html