Real Caller ID is the best Android caller ID app on the market.
Most other services only give you locations for callers. Or they don't even have caller information!
But Real Caller ID pulls the best, most up-to-date caller ID information you can get.
Features also include the ability to see a recent caller list so you can see who's calling you even when you're not there for the call.
Note that if you're a Verizon or Sprint user you'll have to be connected to wi-fi to get your caller ID information live.
This version of Real Caller ID allows you to get caller information for up to 50 calls!