Short of writing an application which will run in the system tray, I can't think of a way of implementing this. There may be applications which could provide this functionality, but I know of none.
Another alternative would be to look into Rainmeter
- It is possible there is a skin available for this. Rainmeter overlays different data on your desktop, and through scripting becomes highly customisable. It has a large, active community creating all sorts of new things to do with it. (Rainmeter skins can be found elsewhere, such as deviantart)
Or, you could look into options for docks, they may provide applets which can provide some similar functionality