While Apple has already announced (in the WWDC 2011 keynote) that you’ll be able to use your iPhone’s volume up button as a shutter in iOS 5, we’ve received a report that its also possible to use the volume up button on your Apple headset to do the same!
The trick requires a pair of earbuds or a headset that supports Apple’s volume up/down functionality, such as Apple’s official earbuds, but shows a lot of potential use, such as being able to set up your phone and snap a shot without having to worry about the ensuing wobble!