Whew I had a nice one last year at the Indy MotoGP race. Me and a friend riding into the parking area inside the track, they are lining up hundreds of bikes to park (of course) and I'm on my BMW r1150rt (sport touring.)
Seeing as how the parking is in the grass, the final guy waving you in to your spot tosses down a kickstand plate. The plates they toss are just stamped metal, there are no grooves in them or anything, just bare, slick steel. You can probably see where this is going...
I kick the plate over to my kickstand and start undoing my gear while sitting on the bike. I look down and put my kickstand down and it appears to be right on the plate. Well... it was, except the plate was halfway in a hole I couldn't see in the grass. Sure enough, the moment I kick my leg out over the bike to get off the bike starts tipping on me. I drop my lid and immediately grab it because they are parking bikes about 24" apart and if this goes it's domino time.
I caught it, but barely... basically I trapped myself between my bike and the one behind me (at least preventing any damage to either bike) and two guys on the other side of me had to run over and lift it up off me.
I had a huge bruise across my backside from where my bike landed on me and threw me into the peg of the bike behind me.
Could have been much worse with all the bikes around.. but it was still rather embarrassing.