It's Thursday, and the Class Designer team is sticking to their new entry every Thursday policy. I don't want to just post a link to their blog every week, but if they keep doing stuff this cool I'll have no choice.
Eugene Chigirinskiy could have just posted a screen shot showing tooltips at work in the class designer. But instead, he's built out an HTML image map on top of said screen shot and set up the areas with titles so that as you hover over areas the screen shot, tooltips pop up the same way they do in the tool. Awesome! I have no idea how long it took him to do this, but that's dedication!