This is great, and highly appropriate for the tick-tocking away of the year -- Japanese modder Nobon had an old Power Mac G5 (case, it looks like, though this would be cool on a working Mac as well) sitting around, and he wanted to know what time it was, so he installed a little clock in there. As mods go, it's pretty simple, but man that looks great. Like most users, I usually hide my actual boxes under the desk or in a cabinet, but if any of my computer cases were as beautiful and functional as that, I'd put them out front and center.
There's a sequence of pictures on his site showing how he did it. It's all in Japanese, so you'll only be able to read it if you happen to be fluent. But it looks pretty simple -- drill a hole in the side of the case, install a battery operated clock, shine a light on it, and voila, instant Mac centerpiece. Apple products don't die, they just change function!