While we've seen dozens of water purification devices before, the Pocket Well falls back on a classic design for easy function.
Modeled after old well pumps (many of which are still in use), you can stick the $35 Pocket Well into any water source (sorta...it seems like it still may require two-hand operation). You pump, and over the course of two minutes the pressurized water is filtered 99.9% free of badies and also treated with minute amounts of iodine as a backup.
Assuming that you don't need to pump nonstop, the Pocket Well seems like a good solution for filtering large amounts of water for group situations—up to 50 liters. But then again, there is a lot of water coming out of our tap at any given moment, too. And it doesn't taste like elephant feces. And it has A/C.