It may have happened to you before -- you're walking down the street somewhere on a balmy summer night when, out of nowhere, the empty car next to you honks its horn and you spit your skeleton right outta that purty mouth. Yeah, you have Zipcar to blame for that. Ever since the introduction of its iOS app back in 2009, users have been able to reserve a car on-the-go, and freak out unwitting pedestrians. Now Android users get to join the party -- officially. While the apps' market availability is nothing new, the re
