Other than the built-in iPhone 4 camera app, what other apps do you use in it's place? Do they REALLY provide an enhancement to what comes with the phone?
I tried a couple and I've found that Camera Plus Pro is the best as far as camera functionality goes.
It can do burst photos (full resolution without delay), stabilization, big button, and also does full res video in app as well (others I saw didn't take full 720p).