Concert ticket dilemma

I bought Radiohead tickets for June 13th as part of making up my long absence to Catherine (at 2x face value!) and then I found out that the Eels are playing for free that night. :-( But it looks like Craiglist has a semi-vibrant ticket forum, so maybe I'll be able to pull off a trade. One cool thing, though, in Google Calendar, you can search for the New York Free Concerts feed, which includes all the River to River shows.