Well I looked around the forum and didn't see too much on this subject here so I'll start the topic:
I have been tracking my snowboarding for the last year and a half or so, via an app on my smartphone. There are a bunch of different options (sportstracker, itrailmap, trekbuddy, etc.). I've been using an app on my Nokia E71 (and now Nokia N8) called trekbuddy to create *.gpx log files of all my days on the slope, and then I upload it to Garmin Connect to see what I've done. I tried a few other apps but didn't have as much luck. I like being able to store the raw GPX files for use on any tracking software.
Here's a look at some of my days, can't figure out how to show my whole activity list...
Nakiska Podwer in the glades
Fernie early season riding (bombing)
Anyway, for those that didn't know just wanted to mention that these apps are out there, as well as specific GPS devices (Garmin, Nike, Timex, ETC). Trekbuddy has a small learning curve but it's very reliable once setup.
Also, I'm aware that this isn't that accurate. I've set trekbuddy to log valid datapoints every 3 seconds, and looking at the GPS files often it only gets a valid point every 5-6 seconds. This isn't meant to be super accurate, but a fun way of pushing yourself and seeing where you went. This year I have a goal of doing every run at Fernie one day, every run at Nakiska another day, and maybe every run at Lake Louise another day. Should be fun!