eBay calculates that there'll be 19 million unwanted presents in Australia this year, and that around 1 million of those will end up being sold. (Yes, eBay would say that.) Assuming you don't feel guilty about selling that item, eBay also calculates that the average selling price is around $76.
If you don't want to go the eBay/garage sale route, then you have two other choices: chucking the present out altogether (in which case a charity donation might be more appropriate), or regifting. We've covered the issue of regifting quite a few times, so we won't repeat ourselves here. Suffice it to say that the worst choice is hanging onto something you won't use simply to avoid offence. Don't start 2011 with a gift-driven clutter problem.
Picture from Tough Pigs