Jumping Icons

One of the most amusing features that I've seen so far with Mac OS X is the jumping icon.  I'm not really sure what the official name of it is, but it is basically a less obtrusive way for a program to get your attention.  If you are familiar with MS Windows, you are familiar with the pop-up dialog boxes that programs can throw up on the screen when they need your attention.  The problem with them is when they pop-up, they usually grab the current keyboard focus, so if you are busy typing away and a dialog box pops up because some program wants your attention, you might accidentally dismiss it before you get a chance to read it.  On the Mac, instead of throwing a window up in your face, the icon for the program that wants your attention starts hopping around on the bottom of edge the screen.  It's kinda cute, and gets your attention in a way that doesn't require you to immediately drop what you are working on, but since it keeps hopping, you also are not likely to accidentally forget the program is still waiting for your attention.  It's a very simple idea, but it's makes a big difference.