So, just when I think I've had just about every imaginable bike mechanical problem, I'm proven wrong. I started riding home from work one day, and I heard this horrible screeching noise. It was kind of off and on, and I thought it might be related to my cleats, since I'd just started wearing different biking shoes. It sort of disappeared by the end of the ride and I forgot about it. Next morning, it came back in spades, and I again thought I really needed to investigate, but not now, since I had to get to work. Most evil bike noises are ignorable, I just turn up my iPod. I was still wondering what the noise was when all was revealed — the right pedal fell off. I immediately opined that the source of the screech was pedal related. In fact, the pedal bearings had pretty much seized up, and the noise was the pedal's plaintive way of telling me that the crank could go round and round but the pedal wasn't going to. So when an irresistible force meets an immovable object — the pedal won. It obstinately refused to turn, so when the crank did, it proceed to unscrew itself from the crank arm.
This is theoretically impossible, since pedals are designed so that pedaling forward has the net effect of tightening the pedal, not loosening it. That's why left pedals have left handed threads (which you may have found out the hard way if you didn't know that). But it happened nonetheless.
I quickly ascertained that poking, prodding and staring at it sternly was not going to make it move. So, what to do? I was by now a few miles from home, way too far to walk. So, then I tried a technique I have read about, pedaling with only one foot. Major Taylor, or some other cycling legend, is reputed to have smoked some mere mortal by pedaling with only one foot while the victim used two, so why not give it a try.
I immediately found out how lousy my pedaling form was. Pedaling in squares is an accurate description. Of course all the fixed gear weirdos are now snickering and feeling superior. Anyway, that got old real fast.
So, I decided to engage the right foot again. I would watch the right pedal and if it started to unscrew again, stop and tighten it. By tighten I mean tighten by hand since of course I had no actual tools. I somehow decided that if I didn't clip in, this would make it better (which of course makes absolutely no sense). Then I decided that as long as I kept pedaling forward, that was good, since we are theoretically tightening the pedal, but that coasting was bad (more snickers from the fixed gear crowd). That of course makes no sense either, since if neither the crank arm nor the pedal is moving, no harm, no foul.
Anyway, I did manage to get it into a state where I could pedal forward without unscrewing. When it started squeaking badly, this was a clue, and I would check the pedal and screw it in again if needed.
Finally made it home, swapped pedals and off to work again. I think from now on I will take nasty noises more seriously.