konfabulator
I'm a mac user. I have a blog. Union law therefore requires me to mention Konfabulator. It lets you put 'widgets' on your desktop - little image / XML / javascript components that do stuff like calendars and clocks and cuteness.
It's all too unbearable for words. I used it for almost 4 hours before it drove me crazy. I have tools that do all this stuff. The default widgets are just not compelling. The one thing that would make it bearable would be if I (a) the widgets were on a layer behind the desktop icons, and not fully-fledged windows, so they don't keep popping to the foreground on top of my other windows, and (b) if I could lock the layout so I can't click on them and they won't take the focus. But then they just become 'further for macos'. Which would be a good thing, actually.
Oh, and the widgets aren't configurable. Hell, resizable would do, I really need a frikking battery meter taking up half my visible screen area. And yeah, all the default colour choices are fine, I don't need to change the colod of the stock ticker (stock ticker? Why do these things always have a stock ticker?) so it's not INCREDIBLY UGLY. Sigh.