Want to check out the hair at the nape of your neck, see what the back of your throat looks like, or look behind places you can't fit your head? If you have an iPhone 4S and Apple TV you can setup Airplay mirroring so whatever your camera is recording is displayed on your TV in real time.
Mac enthusiast weblog TUAW shares this clever use of the new-to-iOS 5 feature. You can enable Airplay mirroring by double-clicking your iDevice's home button, swiping to the right twice, and selecting your Apple TV as your Airplay destination. Make sure that mirroring is turned on, then click on the home button and load your camera app.