It's a microscope attached to a cell phone.
Granted, it's not designed for really detailed microscopic viewing, but it takes an image using fluorescence to highlight certain biological features, such as finding Plasmodium falciparum, the parasite that causes malaria in humans, or sickle-shaped red blood cells.
So, you're in rural Africa trying to figure out what's wrong with a patient. You take a sample, zap it with your cell phone, it goes back to the lab and you get a call shortly telling you they've got malaria. You don't have to ship the sample over impassible roads to a lab someplace far away, you could literally get results from the lab while you wait, and that lab could be on the other side of the planet.
I think the really cool part of this system is that you can do this from just about any phone, you don't need a fancy iPhone or Blackberry, just a phone with a camera that can transmit the image.
It's all about being connected.