I'm looking for a poncho pattern, preferrably free, that is worked in one piece using DPN's.
Wow, that'll be a lot of DPNs at the widest bit! Why not use one of the one piece patterns which call for a circular, substituting DPNS as you wish? Faery Crafty has a very comprehensive list of free poncho patterns. http://faerycrafty.blogdrive.com/archive/199.html