Several websites have been created that allow you to sell unwanted gift cards or buy discounted gift cards.
Card Swap is Canada's version of this fabulous service. They sell discounted gift cards from spas to restaurants.
Plastic Jungle was top on google's results for American discounted gift cards and seems to be laid out similarly to Cardswap.
PS - Wishing you a fabulous start to your 2010... mine will start tomorrow morning as there's no way in heck I'm staying up until midnight. I haven't seen 11pm since my two nights in the hospital when Jane was born! :p