How to uninstall Quickoffice from HTC Nexus One Quickoffice 2.0-GEP is listed in my manage application lists and I want to uninstall it. It's not listed in my programs list. I am not even sure what it's used for. 

When I click on it from the manage apps list all the options (force stop, cancel, clear data etc.) are greyed out.
To remove any system default applications your phone must be rooted. And using this system app remover you can remove the system added applications. But you have to do this on your own risk. 

I have been doing a lot of research on Android mobiles, I can tell that your system might not work properly if you remove any system added applications.
But most of the applications work fine without any issue.

Updated

System App Remover is a paid application. There is one free application called Root App Delete. Have a look at this..