Mac OS X brought with it an abomination of user experience on par with Clippy. They’re known as drawers and essentially they’re little windows which slide out from the sides of parent windows. You can find them in Mail, Preview, and now iCal. You won’t find them in Safari, iTunes, or Apple’s Pro applications. What kills me about drawers is that they aren’t calculated into the width of a window so if you’re trying to maximize the window you’re working in you have to drag it by hand. Worse, if you’re already working in a maximized window, the drawer will slide out off the edge of the screen! This is not good experience design. iCal recently moved some of its functionality from a floating window to a drawer. I hated the floater but the drawer is worse. What’s more, this iCal drawer is something you need to use all the time. Stuff you need access to all the time should not be placed in drawers. Apple’s Mail program has the same nonsense. Safari, iTunes, iMovie and many other apps get by just fine without drawers. Camino has (had?) a nice feature which would resize the window when the drawer was shown, Transmit uses drawers smartly, and the search drawer in the new Preview looks cool. But for the most part, drawers are 99% bad. Sigh.
[Less ranty: Check out the new iPulse. It’s beautiful. No drawers either.]