We just fiddle with the frequency dials first day and get it sorted,have never had any problem, occassionaly have someone else (usually British wishing us a good days skiing!), but thats all!
I have some. The basic cheap type that you don't need a licence to operate in the UK work on about 8 fixed channels. You share the channels with everyone else so I imagine the airwaves are pretty busy in a ski resort.
If you do use them, keep the chat to a minimum... cos I want to use it too!