I love desktop widgets like KDE has, and I was wondering if there are any cool widgets for the Stack Overflow, Super User, and Server Fault family of sites for GNOME/KDE?
There are very few applications out there that offer very good functionality with any of the StackOverflow family sites. This is primarily due to the fact that there is a big barrier in the way of there not being a public API released yet.
This is something that Jeff has stated is in future plans, and once something gets developed and released I imagine you will start to see a massive influx of nifty websites and programs that integrate wonderfully with the system.
There needs to be an API first before we can actually build SO applications. I think that once it is implemented that there are going to be some great apps that will make answering questions even faster and easier.
Until then, you might want to try some Greasemonkey scripts that work in Firefox. I find there are a few that really add a ton of functionality.