If you are a UK resident or citizen please consider signing this petition to help racing greyhounds.
In principle there is nothing wrong with the sport of greyhound racing. Unfortunately, utterly selfish tossers seem to be disproportionately represented among greyhound owners and these people bring the sport and themselves into disrepute.
If you want an example of what is wrong check out this article on the Tia Greyhound Lurcher and Rescue Site.
By the way if you are looking for a good cause in which to invest your spare Christmas cash, you could do a lot worse than donate to Tia.