iOS/Mac: AirDrop is one of Mac OS X's best features, and Instashare replicates its dead-simple wireless file sharing powers on iOS.
Instashare can transfer items from your camera roll to other devices on the same Wi-Fi network or within Bluetooth range, assuming they also have the app open. The interface is simple, but fun to explore, utilising a drag-and-drop paradigm rarely seen on the platform. A free companion Mac app will also allow you to transfer any type of file to your phone or tablet on the fly.
Obviously, there are plenty of ways to move files between devices these days, but Instashare's transfer speed is actually pretty phenomenal. For photos, using iMessage or Dropbox works just fine, but Instashare earns its spot on your phone when you need to transfer large video files. In testing, the app moved a 70MB video from my phone to my computer in about 20 seconds, while uploading the same file to Dropbox took over two minutes.
Instashare is free on the App Store, and a $0.99 in-app purchase will get rid of the banner ad. The developers have said Android and Windows apps are in the works.