I'm gonna try a jansport katahdin 20L daypack inside my big 82L backpack (also a jansport (vintage)). It'll be a little lighter and easier to pack that the 30L daypack (internal frame) that I've been stuffing into the big pack for these type of adventures. There were a bunch of options like the ones that you guys and gals mentioned (marmot kompressor, TNF verto, etc), but I decided I'd rather carry an extra 1/2 pound in my backpack, if it meant being more comfortable when we are bagging peaks on Saturdays. At least this pack will take up less room than the daypack I'm currently using. It also saves me almost 2 pounds. Thanks again for the advice everyone.