Otterbox's cases are tough, but their new Utility Series Latch case can pretty much attach itself to anything, allowing you to use it in almost every situation.
The $US50 case has straps for your hand, leg and headrests for cars. Not only that, but it can hang from your neck via a lanyard and clip onto your belt and whatever else you can think of with its utility clip. If Batman were to have an iPad, this is the case he'd use for it. [Otterbox]