The iPhone 5 concept by Zeki Ozek suggests more benefit in a %23 smaller iPhone. By using a fingerprint reader instead of home button you can unlock your phone with a finger swipe. Assign your fingers for apps. You can assign your little finger for twitter, middle finger for mail.
With a double up-down swipe you can open background working apps. ( When you want to close background apps, the first icon will be close all). The fingerprint can be used as password when needed.