I am a 3D skeptic, avoiding 3D movies in theaters in favor of their 2D counterparts and continuing to enjoy the hell out of all my 2D screens. But hey, I am but one man. If you're on the 3D bandwagon, this new dongle will let you shoot 3D video on your 2D iPhone.
This thing is a Kickstarter project, so you'll need to chip some money in to get it made in the first place, but if enough 3D fans do so you'll get one of the first off the line. The dongle plugs into the bottom of your phone and adds a second camera, allowing you to shoot both 3D photos and video. Of course, you won't be able to see anything in 3D on the iPhone's screen; instead, you'll need to show em off on a 3D TV with active shutter shades.
But something tells me if you're interested in something like this, you already have the proper setup.