I saw a triangle shawl pattern recently that looked super easy, although of course now I can't remember where.
You know that classic dishcloth pattern that has the K2, YO increase at the beginning of every row? It was that exact pattern, except you didn't decrease once you hit the middle. You just cast off.
EDIT: I found the pattern I was talking about - it's called Bev's Dishcloth Shawl! http://www.bevscountrycottage.com/bevs-shawl.html
I also found a page with 314 different triangle shawl knitting patterns: http://simpleknits.blogspot.com/2007...-patterns.html