Summer or winter? You looking for work or just interested in what people do?
I used to wash up at L'Atmosphere in summer. Plenty of that sort of evening work around - with the bonus that you get fed well.
I wouldn't reccommend doing any guiding (ski/board/climb) or instructing work unless you are properly qualified. The money is quite tempting, but if you get caught you will be in serious shit.
I helped out at the Panda club (ski kindergarten in Argentiere). Initially just preparing the snow for the kids, but also helped with english speaking families. Also used to do a bit of childminding for parents who wanted to get out on their own for a bit of skiing or dining - put up ads on the notice boards of the bars.
Ski-tech work is ok. Just ask around the hire shops. Good work to do at night leaving the day free to play.
There are quite a few british builders out there who often need skilled help. Skilled carpenters make a good living working on the wooden chalets.
I've driven transfer vans to and from Geneva Airport, boring but warm and comfortable.
