FWIW, OmniGraffle is the commercial solution on the Mac that pretty much everybody uses. If you're going to be doing diagrams more than every great once in awh

FWIW, OmniGraffle is the commercial solution on the Mac that pretty much everybody uses. If you're going to be doing diagrams more than every great once in awhile, it's worth investing in something good. I've been using it for years and it's what I do all of my hand created diagrams in.