Want to use your iPhone for presentations, but don't want to worry about figuring out how to hook it up to whatever screen is available when it's go time? The Pocket Projector iPhone Case will let you display whatever's on your phone on any available flat surface.
This $230 case from Brookstone features an LED DLP pico projector inside, shooting out 15 lumens of brightness and a 640x360 resolution. It can produce an image up to 50 inches in size, but will probably look much better at smaller sizes.
it also has a built-in rechargeable battery that'll power the projector and also give your phone some extra juice, which is a nice touch. The only downside is how bulky it is; you probably won't want to keep this thing on all time time, instead only pulling it out when you need to use the projector.