QuickShot with Dropbox (99 cents) automatically uploads new snapshots from your iPhone, iPod, or iPad to your Dropbox account. In other words, it effectively turns your iDevice into a "Dropbox camera."
After installing the app, you link it to your account. By default, uploaded photos will land in your eponymous Dropbox folder, though you can choose a different folder if you want (assuming you know its name; the app doesn't let you browse available folders).
QuickShot also lets you choose photos to upload from your camera roll or library, though you must tick them individually; there's no "select all" option. (The same is true of the actual Dropbox app, which, it should be noted, is free.)
For taking new photos, the app works almost exactly like the stock Camera app. You can tap to focus, swap between the front or back camera, and turn geotagging on or off. The only thing missing is support for HDR, which might prove limiting for some shutterbugs.
The beauty of QuickShot is its speed: newly snapped photos are immediately uploaded to Dropbox (unless you've enabled "confirm upload," in which case you choose whether you want each snapshot to go).
Bottom line: If you're a Dropbox user and want a fast, effortless way to archive (and/or share) your iDevice photos, QuickShot with Dropbox gets the job done. It's a great little app.