I didn't list any of the 'other' frequencies because transmitters and receivers which operate in the 27 MHz band are few and far between.
I'm willing to bet there are twice as many of those 'other' tx/rx's out there as compared to 72/75!!! think of all the cheap walmart toys and such on those freqs...
anyway, back to the subject at hand, get your hydrofoam flying yet? mine is almost ready to go, finished up a little more rigging, now just have to paint. (and yes, it is on channel 18 air!)