21–23 of 23 posts
I use Mockingbird for wireframing. http://gomockingbird.com It doesn't allow collaboration but it is entirely focused on wire framing (unlike GDrawings, OmniGraffle and Visio). It provides a great experience. For everything else, I use OmniGraffle.
Omnigraffle is a lot better than this for really making pretty diagrams, because it's connection aware and can do graph layout. Also, if you learn the Keyboard Shortcuts you can be really fast. It's one of the few applications I use as much as emacs, and it's worth learning. People in this thread have been saying pen and paper, but it's (obviously) a pain to scan a bunch of pen/paper sheets for search later or remote…
I see five reasons, and they are all advantages of being cloud-based, rather than a desktop application. There isn't much about drawing itself.
Most annoyingly, the fact that you can't alt+drag or alt+nudge (arrow keys) to duplicate an object. For me that's the single biggest time-saver when doing wireframes and mockups. Otherwise you spend a lot of time repositioning and realigning pasted objects.
Most desktop apps get it right. I've yet to find a web-based app that does.