I'm very superstitious. It's probably due to cultural influence (the 'evil eye' is quite prevalent in every day Iranian life, for example), being around my [maternal] grandmother my preschool years--she had a few but very strong superstitions of her own--and, funnily enough, the lack of a religious upbringing in an environment which was fraught with religion and falling back on superstition to explain life's circumstances.
I am dead serious when I say I believe someone can give us the evil eye. I won't talk about something good happening for fear of jinxing myself and giving fate a chance to exercise some terrible, twisted retribution to counteract it. I really, really believe in karma (although it's sometimes hard to believe it for others, since karma seems to take its sweet time in some instances), and think the universe does (or should!) turn on the principle that whatever you do unto others, you'll get handed back to you tenfold.
It's funny, because I am so prosaic about things in general, but always, always, at the back of my mind there is this little ring of superstition. I try to ignore it and I tell myself sternly that I am an idiot for even entertaining thoughts like that...but I am obviously not very good at knocking sense into myself, because here I am wondering if having merely mentioned the fact that Houdini looked like he had a little colour in his face is why he is got a bad cold.