I take notes in class using OmniOutliner. Sometimes I just want to put a quick drawing in my notes. For example, in physics class, I might want to put a free-body diagram in my notes. Usually I just keep a sheet of paper in addition to my notes on the computer, but I'd like to go all electronic.
What I'd like is just a simple draw program with the basic shape tools, etc. Something a lot like the original MacDraw. I just want to be able to make a quick drawing and copy/paste it into OmniOutliner.
Apple's Sketch example in the Developer Tools package is nearly perfect, except that it can't put arrows on the ends of lines, and it doesn't have any kind of alignment grid.
Any ideas? I couldn't find anything on MacUpdate. I have Illustrator, but I don't want all that overhead... just a small, simple drawing app, preferably free.