I use a Webtex Camelbak clone for overnighters, it is not very good as it leaks if water gets to the screw lid thingy. I have to find that old Ortleib 4l. baldder I had a while back.
I have just got some of those water collectors for my hammock from an Ebay auction, you screw a pop bottle to them and hang them from the corners of your tarp.
Problem is whenever I go bivvying it seems to stay dry, I am not complaining you understand.
I also sometimes use a Nalgene bottle.
Stewey.
Good Stuff - what did you think of the Ortleib 4? I'm wanting something secure to carry water in and that was on my "must find out list".