Born last year out of an April Fool's Day joke, the iCade is a bluetooth controller for games on iOS that is stored within a minituare arcade cabinet.
iOmega, the company that produces, has just introduced new versions of the popular device at CES. iCade Mobile serves the same purpose as the original, but isn't as bulky. iCade Jr. will provide the same effect for your iPhone or iPhone Touch. iCade Core actually attaches to your phone or iPod to make it into a physical controller.
Few games support the device, so it's little more than a pricey novelty, (the original is $99,) but definitely a conversation starter.