weatherbug has had a pretty notorious history for being a piece of spyware. they CLAIM to have cleaned up their act, but that is up in the air... there are alternatives to it...

http://tropicdesigns.net/weatherpulse.php

also, my personal recommendation is go firefox and use the weatherfox plugin. it puts a very customizable forecast on the bottom right corner of the status line of your browser. (you can move it anywhere actually)