The folks at work organise this sweapstake every time there is a horse race or an important football event, i.e. Euro Cup/World Cup.
I don't care much, because I understand very little about football and even less about horses. But that was easy - just pick a paper from an envelope and wait for the result. So I took part for the first time and guess what? My horse - New Approach - won the Epsom Derby 2008. :-)
I got £10, enough to by lunch, and my hapiness for the day.