Though we live in an age where robot helicopters can juggle, and Mercury now has satellite TV, but cross platform co-op is pretty rare.  Playing the in the same game as your Playstation 3 owning friend while on your Xbox 360 is pretty much a pipe dream.  But maybe a game could talk between two different platforms if, say, they both had the same manufacturer?  That's exactly what has happened with a new iPad/Mac game, Guerilla Bob.