Common fix to "waiting for activation" - iMessage and FaceTime

I posted this as a reply in another discussion and have been getting "thank you" replies nearly daily, so I assume this is the correct fix. This worked for me after my iMessage had not been working for a couple of months. I was also not getting texts from a handful of my friends at all, but now I do. This also worked for FaceTime.

Just update your date/time settings:

Settings

> General

>> Date & Time

>>> Set Automatically: Slide "ON"...If it's already on, then slide it off, chill for a bit (maybe restart it), then slide it back on.

I am using an iPhone 4 with iOS 5.1, but other users with 3GS, 4S, and even iTouch devices replied that it worked.

If it works for you, give me some likes!