I'm really superstitious when it comes to sports. If I'm watching football or hockey or something and my team is doing bad, I'll leave the room because I just have it in my mind that it's my fault they are losing since I'm watching. If I'm not watching but it sounds like my team is losing from the angry shouts of my family, I have to go watch. Or... you know, sometimes my team just plays better when I'm in front of the T.V, but I'm not watching the game, so I'll sit there reading and only watch the replays. I know it's stupid and it is clearly not my fault when they're down, but I do it anyways.
I also knock on wood every time something bad happens or, in the case of watching sports, someone in my family or the announcer says something that I think will jinx my team. (And in the case of actually playing sports, any time my team is down or someone says something to jinx the team... my coach makes sure there's always a wooden clipboard around so I always have wood to knock on)...
Again... I realize that all of these things are clearly ridiculous, but I still do them.