OmniGraffle is why I go on osX, 9 times out of 10. I've only got one issue with it, which I've installed 10.2 in order to overcome. I'd be interested in any new info on this issue, how long it oughtta be 'til it's no longer one, etc. etc.: http://www.omnigroup.com/applications/omnigraffle/support/content.html#papersize