+1 on the Jeff's gear hammock. I haven't really used it as a gear hammock that much but it makes a great pack cover. I stitched a loop of crossgrain on the inside/outside about 1/3 from the top. I put a biner on each loop then clip the outside to a tree strap and the inside to my pack hang loop. It lets enough of the cover wrap over the top of my pack to keep my shoulder straps and waist belt dry in a downpour.
You could do the same with any pack cover but I like the multi-use aspect of Jeff's. Go with the bright orange in large. You'll never lose it.