[via ubuntugeek.com]
NameBench is a program that searches for the fastest DNS in your area. After the program is finished searching and comparing between DNS it will give you the results including the fastest and nearest DNS in your area. After that all you have to do is edit your connection settings to use the fastest DNS available.
NameBench is available for Windows and Mac systems, but most importantly it is Linux compatible.
Prepare your system
Install the following package
sudo apt-get install python-tk
Now you need to download the .tgz file from here

