mgrant
I have the 18 Litre Cortech magnetic tank bag and I love it. It is expandable by opening up a zipper just like a suitcase and if the weather goes south and starts to rain it has a built in cover that can pull over in a jiffy. Pockets for sunglasses, Key clip, Cell phone, Map cover, I put my GPS in there sometimes. I carry my spare tinted or clear visor for the skidlid a waterbottle and some tools for the just in case. All in all a well engineered good bag that I have been real happy with. I picked up mine from G.P bikes at the Toronto bike show a couple of years ago but I have seen them at kneedraggers.com
Cheers
CNN