Do you have Tiger "Widget" envy?  Konfabulator is available for both Mac and Windows PCs, delivering a solid level of polish and productivity (if you can call it that) to your desktop, even if you don't have Mac OS X "Tiger".

What's more, the new Konfabulator 2.0 is out with redesigned plug-ins and enhanced APIs.  While I cannot vouch for system resource usage or security- they may have have issues like Apple is having now with its own Dashboard Widgets.  At $19.95 to buy and free trial.  Be sure to check out the Widget Gallery.