Originally Posted by
old's'cool
Not a high end bag, but very functional and good value: the Performance Bike Transit "Metro" messenger bag. It's a pannier that converts into a messenger bag. I've been using it for a year. My only significant complaint is that the retention system on the pannier is hokey and awkward (or else I'm just dense!). Anyway, I figured out my own retention system using rubber tiedowns that is robust and fairly easy to use.
I also have this one. Good, although you get what you pay for; the fabric started fraying a lot after a few months. Also, I've had it jump right off the rack when going over big bumps, even when it was as tightly attached as possible. Plus it's kinda ugly.