It's useful to scan for your device. In a room with heaps of devices, you can turn yours on and off a few times to figure out your MAC.
$ hcitool scan
Scanning ...
10:93:E9:0C:E8:2D Raiden
20:14:03:27:23:76 n/a
00:17:E9:6A:BF:D4 Pebble BFD4
78:31:C1:BF:B6:A9 James’s MacBook Pro
B8:F6:B1:14:6F:BA n


