Well, like any 9yo Canadian, hockey cards of course.

I sure some people remember those days. You'd get your weekly allowance, spend it on packs of hockey cards, and see what'd you'd get. Then once a month the magazine would come out, explaining exactly how much each card is worth. So you and your friends would piss around trading cards, then every once in a while you'd goto the local store to cash in some cards for that whopping $3.50.
But nah, my first real business was online software when I was 17. Did pretty decent too. Just before I turned 16 my parents moved me to Texas, then the UK. I was a bit pissed at the whole ordeal, so figured out how to make money on my own, and by the time I was 17 I had a good $10K saved up, and was ready to move back to Canada. My mom almost shit herself when I asked the one morning if she could give me a ride to the airport, because I was going back to Canada. They had no idea what I was doing.
