Recently, I picked up John Barrow's One Hundred Essential Things You Didn't Know You Didn't Know: Math Explains Your World at the library. It's a nice little book of (usually) elementary but very interesting mathematics and statistics. Each little tidbit is about a page or two long, so it's an easy book to just pick a random page in and read.
One of his examples details how to even the odds with a coin, no matter unfair it may be. The only requirement is that it is consistently unfair.