This is a brand new Arc'Teryx Carrier Duffel Bag (40L), ready for you!  Two removable padded shoulder straps, some carrying straps, and full weather proofing make this an awesome grab-n-go bag for 1-3 day trips.  $120 and shipping (won't be much, this thing is light!).

"Battle the roads in search of new destinations with everything you need packed inside the Arc'teryx Carrier 40 Duffel Bag. Arc'teryx's AC² Advanced Composite Construction uses highly water-resistant fabrics and taped seams to protect your valuables from weather, and the bag's nylon ripstop is so light and compressible that the Carrier can pack inside itself for compact storage. Handles on each side and removable shoulder straps let you carry this bag however you like."