you can sell your bib... although it's illegal and I might get grief on here for doing it.... but honestly, if you're not in the top 100 of the race, does it really matter

I had a marathon entry and then they found a tumor in my neck, so I was cut off from all sports activity that summer. I sold my entry.

You can put up a sale on craiglist or another runner forum and you can sell it for cost or under or even a profit if that's what you want. I always sold mine for cost just to get my money back. Print out your confirmation, etc... so they can get the running packet come race time, etc...

or (I just thought of this), can't you defer your entry to next year? I'm thinking you can... check into that. Defer it to 2012, and find another one to run this year