This is a quick & dirty nVidia GPU monitor Docklet I have just created mainly for myself and my darn 8800 GTS card that has been running quite hot lately. It uses nvapi from nvidia to query GPU Physical procressor(s) for temperature readings.
It is a very early beta, that is not very customizable. I will be adding more features later (like letting you select the GPU you want to monitor, or the temperature sensor to display) right now it only show temp readings for the very first sensor and GPU found.
Try it out if you have nvidia based graphics card. Any feedback would be greately appreciated.
BTW: It only work for nVidia cards. I am not sure if something similar could be done for an ATI based one, neither I have one to test with.
Update: 06/10/2010: Added option to show temp in °F/°C
NvMonitor - 0.1.0.0b.zip