420 was the number on some guys paintball jersey that I saw a little while ago. I just smiled at it when I saw it, lol.
Last year at the marijuana march in Toronto I saw someone holding a sign that said 420. Shit was so crazy!
Lots and lots of song lengths. Also whenever I see 419 or 421 on something I always think "one away from 420 duuude!!!" in my head, even though I think the whole 420 thing is stupid. I can't help it though.