Using the terminal I find it annoying when you have to keep typing in 'sudo ....'.
This blog post highlights how to get around this in a little more detail romkey.com.
I found this useful, however I find it quicker just to assume root:
In this file find the following
%admin ALL=(ALL) ALL
Then just add your exception below:
tom ALL=(ALL) NOPASSWD: ALL
(change my name with your username)
Save, and your done.