Touch the puddle, smell your finger (only acceptable time to smell your finger...), does it smell like sweet coolant? If yes, issue. If no, does it smell like oil? If yes, problem, if no, does it smell like nothing? If yes, that's most likely just A/C condensation. This last option is the most likely option.
Edit: Dang, you posted that last night so you probably can't do this. Oh well, I'll leave it for future reference.
Another suggestion to you, drive your car again. Park it, wait an hour, go out and check. If you see no liquid...take it around the block a few times with the A/C on and then repeat the test. If you see a puddle and it's in the same place...you have your answer.
The more relative humidity there is in the air, the more water the A/C will produce. I don't know about where you are, but here in Hampton Roads there's been enough humidity to turn our A/Cs into Super Soakers.