Sketchcast.com eliminates that old pencil case and allows you to create and share sketches online within minutes. You can embed it on your website (see blow) or send a link in an email. You can also grab someone’s RSS feed and stay up to date on their sketches.
While it’s going to be easier to use with a tablet it’s got a lot of quick, fun uses. Sketch a note to the kids, sketch your thoughts to a loved one, etc. I’d like to see them add private areas and a way to add to sketches or mark-ups. In the meantime, it’s a cool way to get a quick sketch to someone.