Pay attention to this group. I noticed them before purchasing an iPhone actually. They presently offer only 2 Apps but this is certain to change.
Their ClearCam takes multiple shots and stacks them somehow to make an image 2x the native pixel size in the camera. Trials with my iPhone4 produce 11.2 mp images and they're good. It had been a "Jailbroken" only App but they've gotten their iPhone4 version through the Apple qualification process. It's on sale for $.99 which is $9.00 less than the jailbroken cost a year ago. The App will also quickly take 3 images compare sharpness and save the sharpest one. Not a bad feature particularly in lower light.
Their other App, RedLaser is free...I love free. This App reads barcodes and has the capability to comparison shop the item read. This is evidently the only iPhone barcode reader which works without add-ons like lenses etc. I've tried it twice, it's fast and accurate.