The eberlestock blue widow compresses down really nicely. It has a fanny pack that is attached to the top of the pack when in transport mode, and you can take it off and wear the fanny only, for hunting out of a spike. I don't really like the way a fanny pack is worn so in the future I'll just compress my pack and take it with me with the fanny inside of the pack with essentials for the day. That way if we kill something I've already got the pack and can pack the first load back to camp if need be. My only complaint with that pack is that it's a little on the heavy side IMO, but it's super comfy as far as back supports and straps and what not.
