Thanks for the replies.
My present bike has a Tioga bag. The problem is that I have a brand new bike. I also got the shop to put on silicon grips as well as extra brakes. It all looks pretty good and I know it took them a long time. I don't really want to have to get them to do everything again so I'm thinking of getting a seatpost bag.
This is kind of what I'm thinking of getting. I've never used this style before but I don't like the traditional panniers.
http://bicyclewarehouse.com/product/...=www.qbike.com