I did on Sunday, that was... interesting. Been training for a canoe/bike/run triathlon and had been canoeing hard for about two hours. I then came back to camp just long enough to take my shortie stem off and put the original longer one back on, because those shorties suck going up hills. So now my upper body is nice and tired, and my front end of the bike is unfamiliar.
I ride about 9 or 10 miles, getting nice and worn out but still going fairly fast, and come to a small bridge going over a creek that's about 6 feet deep. It's about three feet wide, 10 feet long, and it's made out of 2x8's with 2x6's on top, with no ramp going up to it, just a square entrance about 9" high. I pop up my front end with the usual effort, which I *assume* wasn't quite high enough, because before I knew what hit me, WHAM, face plant right onto the bridge. My front tire never made it over the lip, but my bike did keep flipping over and landed on top of me on my back. I just laid there for a few minutes in pain, looking like I was dry humping the planks. I was ok though. Just a bruised ego. Felt kinda silly crashing into a clearly visible miniature wall of wood.