I've got a friend who surfs Stub Hub the day of concerts. The show she sees for the price is crazy. Misses some opening acts but people will dump tickets at the last minute for dirt cheap.
When I was in London I used that service that's like Stubhub. I can't remember what it's called but it was on ESPN. Anyway, I got two tickets, 12th row, to the Titans/Chargers game for $35 a piece. I was pretty happy.
That was a really good show. Those guys worked their asses off. They had huge scaffolding that lowered from the ceiling so they can run into and over the crowd. Some of the songs on their new album I wasn't was wild about compared to the album before that but in concert they turned into these hard rock jams. The laser and lights were insane. Also they lit a car on fire which is always fun. That was really fun.