2001 Ford Mustang SMOKE! HELP!

Hi Guys! I have a 2001 mustang v6 vert with just over 74K miles. Recently I noticed a small oil leak where I park my car. Now when I drive it and come up to a stop, the engine has small wafts of smoke coming out from under the hood. Smells like burning oil to me. I can't figure out where the leak is coming from. Today I turned on the a/c and it wouldn't smoke when I was at a stop, but when I turned off the a/c, then it'd smoke again. Also, I checked my oil, I'm down about a 1/2 quart. My temp gauge and oil pressure gauge are right where they should be.

Any ideas??