Currently, I don’t think there’s any specific AP locating software. I read a news piece the other day about a company that is working on location info for AP’s based on the time delay. They intend to incorporate it in security products. For example, you won’t be able to connect to the AP if you’re too far away, rogue AP’s that are outside the building won’t be able to authenticate, etc. But there’s nothing today. The best you can do right now is use a directional antenna, signal strength measurements, and triangulation to locate an AP.