Here’s a hidden gem inside of iOS 4.3 that hasn’t been mentioned by anyone as far as I know. It was pointed out to me by an anonymous tipster, who sent me a few screen shots.
Apple is now allowing you to purchase Ringtones directly from your iPhone 4 (I’m not sure if this is supported by other models, but I suspect it would be).
Here’s how it works.

On an iPhone 4 running the iOS 4.3 Gold Master  launch the Settings app, tap Sounds, tap Ringtone, and then tap Buy More Tones.

You’ll be taken to a Ringtones store which currently seems to be overrun by Lady Gaga and her expensive $1.29 ringtones.