Shake to Undo and Redo Typing on iPhone, plus a bunch of other iPhone tips
I finally got around to installing iPhone 3.0 on my iPhone 3G and I’m pleased to discover some of the new features available, but I must say the one I’ve found myself using the most (other than copy/paste) is the ability to shake the iPhone to undo and redo typing in any place where you have inputted text, this is basically the equivalent of Command-Z and Command-Shift-Z in Mac OS X. So cool! I’m pretty thrilled with the iPhone 3.0 OS update, and there are a ton of features and tips out there, check out some of these links for highlights:
iSmashPhone: How to use the best 40 features of iPhone 3.0
MacLife: 16 Tips to become an instant iPhone 3.0 Power user

1st link not defined well…
[...] you’ve used an iPhone or iPad much, you’re undoubtedly familiar with the ‘shake-to-undo’ feature that lets you literally shake the device to undo an event or clear a text box. With a little help [...]