Wow, not a single reply of "Your mom!". Having somewhat trigger-happy mods here does have some definite advantages.
I just got up a few minutes ago, so the stupidest thing I've done so far was to check The Escapist rather than immediately getting ready for work, especially since my flexible schedule means that the sooner I get into work, the sooner I get to go home. Unfortunately, that's unlikely to be the stupidest thing I WILL do today.