Everybody wants widgets

Apple had them through Dashboard.
Linux had them with Karamba & SuperKaramba.
OS X and Windows had them with Samurize, DesktopX or Konfabulator (from now on Yahoo Widgets),
Microsoft has them with Gadgets (don't worry, it's the same stuff)
Firefox has them with Firefoxit.

Google wants it too... so here is Google Homepage API. (see some examples)

Incredible what desktop & web customization can do.