There are huge numbers of accessories and gadgets you can buy to make your time on the slopes safer, easier and more fun:
A good rucksack or 'day pack' is worth investing in - they're great for keeping extra kit in that prepares you for all eventualities and weather conditions or just for carrying a packed lunch and a camera. Look for one that secures around your waist and chest as well as over your shoulders - this stops it from moving about too much and unbalancing you while you're skiing or boarding. Lots of these now come with some sort of pocket for a water 'bladder' and tube so that you've got liquid refreshment on tap all day. Snowboarders should look into getting a pack that you can strap your board to, if you plan to go hiking or climbing off-piste.
Motorola two-way radios are excellent for keeping in touch on the mountain - they have a range of about two miles and are small, lightweight and water-resistant.
Avocet watches (as well as telling the time) also give you a wealth of information, such as your current altitude, how many runs you've done since it was last reset and how many vertical metres you've travelled.
Swatch Access watches are also very useful if you are going to one of the many resorts that now have the necessary equipment to allow you to use them as a lift pass: a micro-chip in the watch is 'loaded' with the details of your lift pass and at each lift you just point the watch at a scanner and you are let through the gate. You don't even have to lift up your sleeve, let alone dig your old-fashioned pass out of your jacket.
A Lowe Pro action camera for recording your adventures on the slopes is a must if you plan on showing off your snowy escapades to your friends.