A great hairstyle can really define your style, but it's difficult to know if a particular cut will suit your features. With the Hair Makeover app for iPhone (there's a free and paid version), you can take some of the guesswork out of choosing a new do. Just upload a photo of yourself to the app and choose from nearly 300 different haircuts to virtually try on, and both men's and women's hairstyles are available. The app has a Facebook and Twitter uploading option, so you can poll your friends to see which hairstyle they like best on you. When you decide which one you might like to try, you can save the photo to show your hairdresser.