Ordered 3 copies of this yesterday - 2 PS3 (me and a friend), and a copy for the 360 for myself.
Borderlands was one of those games that got so cheap after it came out that I bought it for everyone I knew hoping to find people to play with. I think I bought 8 copies of it for friends.
I just got around to playing the Clap Trap DLC last night. The Bioshock quote/parody cracked me up.