The Houdini packs down in its integral pocket to just slightly larger than a male's clenched fist - thus it always sits in my bag, ready if needed.
I'll have to see if I can get one on sale.
You could also reduce bottle weight by substituting a recycled Gatorade (or equivalent) bottle for the Nalgene.
My Nalgene fits in the carrier, and I don't think a Gatorade bottle would.