Wow. I'm dizzy.

I've been dizzy for the past hour or so now. Not so that I feel like the room is spinning, but enough that I'm afraid I might fall over while walking. Vioxx sometimes does this to me, but I haven't taken that in about 4 days. And while I have something like allergies or a spring cold, I haven't taken anything for that either. I don't think my sinuses are messed up enough to throw off my balance. Can't be hunger, because I had a mid-morning snack about half and hour ago. What's up with that?