I read about this extremely simple fly designed by Hans van Klinken in a magazine article a month or two ago. It has been by far my most successful dry fly this summer no matter if there are caddis or mayflies on the water. I've tied some with tails and a shorter wing to closer imitate mayflies, but I don't think it matters. I'm not sure if it is the way it sits or its outline or what, but it has been better than great for me.

http://www.flytierspage.com/hklinken/parapoly_sedge.htm

Joe