Fun article from Wired magazine Gadget Lab if you’re going to be downloading Apple’s iOS5 to your iPhone. The piece is called "iOS5: Exploring 7 Hidden New Features."
Here’s one of our favorites from the piece: "You’re in a high-powered business meeting. Your phone volume is mute because you don’t want to offend the client. But you really need to receive that critical phone call from your pilates instructor scheduling a rain check. By assigning a unique vibration sequence to any contact, you can leave your iPhone on the table and listen for the sweet euphony of a customized “zizip, zizip” as your device resonates against the table top."
The article explains, step-by-step, how you can set this up using iOS5.
Other fun features mentioned in the article include getting alternative map directions and creating LED flashes for visual alerts.