I've driven with snow chains before on boarding holidays. They really are f*ckers to fit with cold hands! That was in a people-carrier, but it does make a hell of a difference in thick snow and inclined roads. It all depends on the snow conditions really, and if the roads aren't that hairy they're not worth it in mild conditions, just drive sensibly.
If you're driving to the Alps, they will sell them in petrol stations when you get close if I remember rightly, if you have standard tyres you shouldn't have any trouble getting a set. If you don't know already, here's a couple of tips for driving in snow:
Always brake before a corner, never during it. The car will stop turning if you do and off the road you go.
Sometimes you press on the brakes and nothing happens! This has happened to me before, something to do with snow getting in the tyre treads and reducing friction I think. If this happens pump your foot up and down on the pedal until they bite.
Happy boarding
