Apps for taking pictures on iPhone?

[Lauren]

Today I'm going to get an iPhone, most likely 4s, if not 4. I absolutely love taking pictures and I'd like to start taking pictures on my iPhone. I have an iPod touch, although it's a second generation and therefore doesn't have a camera.
I was wondering (from both iPhone and iPod touch users) which apps you find useful for taking/editing pictures. I would prefer them to be free, but if they're truly a good app, then I don't mind forking over a couple of dollars for it.

[Kevin]

I have the iPhone 4s, and I use a few different apps to either edit, or take pictures from within the app. My favorite apps are:
PhotoStudio
iMajiCam
ColorSplash
ColorBlast
PS Express
PhotoGene
iCameraHDR
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