Emailing in resumes is one way to do it, but meeting reps face to face and following up with a resume is a much better way. Like it has already been said, companies receive hundreds of sponsor me videos, letters, resumes etc. If you meet your local distributor/rep around town, and get a letter/email referral to the Team Manager, your odds of success go up. SIA is a great opportunity to meet people and get some face time, just make sure you have all your ducks in a row. Video, photos, results all help. Just realize its a partnership, what can YOU offer them in return for them assisting you in either product, travel budget, and so on.
The economy is not doing so hot right now, so a ski company giving you one pair of skis needs to equate to a greater dollar value return for them. How will you make that happen? Once you do get sponsored, retention is your next mission. You NEED to keep them updated on what your doing, your travels, results, photoshoots, and continue to uphold a return in sales for them, or exposure via published images, high profile event results, movies etc. Realize that a lot (but not all) reps are stuck at a desk most days, and sometimes seeing your updates can make their day, and you will stick out when it comes down to the wire when they need to make cuts. Look at it like a job.
Feel free to PM if you want any specific advice..