if i remember correctly, all the AAs are on the 27mhz frequency, so its not possible to get more frequencies at the moment (someone emailed spinmasters and they said they were working on getting more though, who knows when though). there is however, a way to change what frequency you're on (A, B, or C) with the flip of a switch. each TX and RX are capeable of using A B or C channel, its just a matter of soldering in a micro switch to change between the three. i attatched a couple pictures to show what i'm talking about. this wont allow you to fly with more than 3 people, but it will let you change which channel you're on if you need to.

a side note to the channels: channel B is the best in my opinion. the frequency changes are created by the frame rate of which the TX sends its signal to the RX. this means that one channel has a slower frame rate and one has a higher. a slower frame rate will result in that pause between giving throttle on the TX and the motors responding. channel B has the highest frame rate, A has the 2nd highest, and C is the lowest. i cant remember off hand, but i read somewhere that bridging all the 3 channels will basically combine all frame rates together to give an overall faster response time between sending and recieving signals. i havent done this myself, so there may be more to it. i'll try to find more info on it.

nick