I'm selling a SINGLE (one, uno, un, ein) Ortlieb "Bike-Packer Plus" rear touring pannier. It's brand-new, never used. So what can you do with one pannier? It's great for commuting, shopping, general around-town use, day tripping, etc. Or maybe as a spare for your existing set (Ortlieb does not sell single panniers). How often do you really need two panniers, unless you are actually touring?
Color is red for maximum visibility and safety on the road. It has Ortlieb's "Plus/Light" fabric, which is a waterproof Cordura nylon. Expandable inner sleeve with drawstring and a top hood that fastens with buckles. Has a mesh pocket and a roll-top waterproof pocket on the front. Uses Ortlieb's easy-to-adjust QL-2 attachment system on the back. Super-easy to remove when you get to your destination, just pull up on the handle and you are off, but it also locks securely to the rack when riding.
Works great on all types of racks, including Blackburn and Tubus.
$99 shipped in lower 48 states. I can't seem to get pics to post here; see them on my Craigslist ad at http://philadelphia.craigslist.org/bik/2097199020.html