If you are the administrator of the APs, then just log into them and view the interface to get the MAC address of each AP. Or if that isn't possible then use WiFiInfo and stand next to each AP to ensure you are connected to the nearest one, then make a note of the MAC address that WiFiInfo is reporting.

You'll need to make a note of the MAC addresses anyway for any of the scanner software to be of use, since they all report the MAC address. There is no other info in the Wi-Fi packets that would identify which particular AP signal you are seeing.

Kismet is good, but unfortunately it is not working well on the N800... it stops picking up packets after a few minutes. But for the few minutes that it is working, it does the job.