Several folks have posted different ways of putting up a tarp shelter, and have provided some very good information.
I discovered this site (http://nwwoodsman.com/Articles/TarpSetUp.html) that covers canoe camping - and there was a very well done article on a versatile tarp set up. I've not seen it linked here before, so thought I'd put it up for folks to check out for themselves.
The site has other interesting bits of field craft as well.
