Fast Pack is a sportbike tail bag that wraps around your rear seat, expands up to about the size of a tank bag when you need it, and collapses down to a custom seat cover when you don't need it.
Check out a review of the Fast Pack at http://www.2wf.com/content/view/1675/45/
Check out a review of the Fast Pack at http://www.2wf.com/content/view/1675/45/