Email 'n Walk
Sometimes an iPhone app comes along that seems crazy, but turns out to have redeeming values. This is just such a case. Email 'n Walk does something amazing. Using your iPhone's camera, it displays a live view of the world in front of you above a virtual keyboard. Now, in the spirit of walking and chewing gum, you can walk and send e-mails at the same time, while reducing the risk of stepping into traffic or falling flat on your face.
As you walk and type, the text of your message appears in semi-opaque letters over the live video feed. When your message is complete, click "send" and Email 'n Walk transfers the text to the iPhone e-mail app. Just choose the recipients and fire it off. Email 'n Walk takes multitasking to a new level.