In reply to Dominicandave:
I used to work for neilson's as a ski/snowboard rep and they like you to have a high standard of ski/ boarding ability. I applied through their website, I wouldn't bother registering with an external company. Contact each individual company directly, most of their websites will have a section on jobs if not search for head office details and ask for HR.
Most positions will be filled by now, but there is a quite a high turn over of staff. As it's not all about slope time. After a few years I ended up working in their French head office in their finance section and I had more time out skiing and boarding doing that than I did as a rep
Good luck doing winter seasons was one of the best things I ever did