In reply to mark hudson: As part of my work, I have tested two way radios in all sorts of conditions including the Alps, Andes, Kili, Dolomites and Caucasus - also in desert conditions and in rain forests. The simple answer is you get what you pay for, but for what it's worth, here is my recommendation.
Kenwood Electronics do a model called Funkey 446. It is not commonly available in the UK any more but if you google search, you will find some stockists. You can get them from mainland Europe dealers though. It is quite a bit more expensive than the competition, but as I said, you get what you pay for. It has various things going for it, like being built on an aluminium chassis which means it will stand being dropped better than any other model in the "consumer" PMR 446 market. All others, including the Motorola are components glued into a plastic case. There is a new chinese model out which is in an Alloy, rubberised case - very tough, but the radio does n't really work. The Kenwood uses the same audio components as their hi fis, so sound quality is top.
On the "professional" side - i.e. bigger, tougher, longer battery life etc, the acknowledged market leader in licence free radio is the Kenwood TK3201. The problem with using "professional" radio on skiing/climbing trips is that they have to be recharged from mains - or as we did on Aconcagua - solar panels.
It really depends what you are going to use them for. If you just want to have a chat and arrange where you are going to have lunch, then I would wait till you get out there and buy something cheap, then bin it at the end of your trip (or sooner - because they WILL break), but if you are depending on them, spend the extra money.
If you want any more info, drop me an email.
Cheers
PK