The PhysOrg page, always a good source for the latest science-related press releases and news clips, has an interesting story about flipping coins. A trio of California researchers studied a large number of coin flips and determined that they are significantly non-random. Apparently the position of the coin before the toss is likely to be how it lands -- in other words, put the coin face-up on your thumb and there's a better than 50 percent chance of getting heads.
Long-time gamers (and probably most compulsive gamblers) know all about dice superstitions -- discarding dice when they give you "bad rolls," or keeping some dice unused to preserve the "good rolls" in them. My favorite was always the Stalinesque method of destroying dice that give bad rolls, in order to frighten the others into cooperating. These are somewhere between jokes and urban legendry -- except that they may not be, after all. Because if coin-flips are partly influenced by the starting conditions, it seems likely that dice rolls would be, as well. The greater number of possible results could make the effect less noticeable, but it would still be interesting to test.