This morning, I woke up intending to go to the grocery store early, but when I went to get the bike, my front tire was flat. I spent oodles of time trying to figure out WHY it was flat, there were no punctures in either the tube nor the tire, no poke-through of the spokes, no brickabrack inside the tire wall, and the tube seems to be holding air, and not making any hissing noises. I've pumped it up again, and am going to see if it is flat as a pancake again by tomorrow.

Cause of flat: Mystery! Looks like I'm off to the LBS to blow money on another set of tubes. Yay. I keep telling myself "I'm saving money on gas. I'm saving money on gas.", but the money still seems to be draining out of a leak in my wallet!