I bought an Icon Urban Tank Bag and I really like the thing. I haven't used it as a backpack yet, but I'm sure I would have enjoyed that feature at the Cripple Creek bike rally. I like the fact that it has smaller pockets on the sides and a huge compartment in the middle. It also has a huge pocket on the bottom/back for an mp3 player. I put my Chatterbox in there and there is tons of room left in there. I need to put two cord grommets in it to make it complete. I keep my mp3 player in the map pocket so I can change songs, so I need to put a grommet there and on the back of the mp3 compartment so I don't have any wires exposed.
The magnets seem kinda weak compaired to my old Joe Rocket bag, but they are doing the job just fine.