According to last Sunday's Mercury News, Stanford/US Santa Cruz researchers have shown a coin flip is not actually a 50% chance as we might commonly believe - it is more like 51-60% towards the side that is facing up. I'd love to see the Mythbusters do their own take on this one, along with related variations such as the size of the coin, weight, etc that could possibly factor in.

They did some research using a penny, and they said that if you flip a penny 10,000 times that heads would not come up 5,000 times but more like 4,950 because the head side of a penny is a little heavier then the tails side.

This is actually a new research report that has come out. I believe you are referring to the 'bread up or down' episode? I don't think they have done one specifically for a coin flip that I can remember. However the big difference that any previous inquiry used is that people did not note which way the coin was facing before the flip. The report is saying you can basically have a better shot at getting the outcome you want by having that side face up before you flip. This might allow someone an advantage if they see which way the person is holding the coin before the flip, and challenges the idea(myth) that a coin flip is 'fair.'

Statistically, it is a 50/50 chance. Practically speaking, it is not so much.

I used to be able to flip a coin and make it land spinning on its edge...does that count?