I don't know how long these will be available, but for the price they are pretty good. http://www.rei.com/product/785138/seattle-sports-deluxe-deck-bag-special-buy This is a sea-kayak deck bag, but if one squints at it properly, it's obvious it will function as a small pannier, tank bag, top bag or a variety of other applications. The straps make them pretty simple to lash up. There's a reflective panel on the bottom. In my experience, the zipper closure is actually fairly dry -- it's the same one used on dry suits. The best thing is that REI is offering 20% off one item just now, and free shipping, so a pair can be had for $43.00 USD or a single bag for $19.00 !