Great post on tarp shelters up at the main page!  (If it was included in the site before, I'm sorry I missed it.)  
But all that outdoors origami is for a square sheet - and many of us use the trusty old - retangular - Army poncho for our tarp/sheltering needs. Seeing a great opportunity to soothe my inner Gropius, this weekend (wife depending, of course) I'm going to get out a couple of ponchos, some poles, rope, stakes, a digital camera and......  we'll see what happens.  A couple of Bloody Mary's may be included to get the creative juices really flowing.
I'll post the results soon.
If any of my fellow forum members have any creative tarp/tent designs or ideas for the humble poncho, send them on.  Bloody Mary recipes appreciated, too.
     .....CLIFF
"Doctors can bury their mistakes.  Architects can only suggest their clients plant a few vines."
   - Frank Lloyd Wright