Underclocking a graphics card...

Is it worth it? I have a 9800GTX(look at spec<----) and it seems my pc uses about 180W idle(with speedstep on). I was thinking about underclocking my card as my pc is idle about half the time its on load, what software should i use? Im looking for something that will allow me to save as a profile since i need to switch from underclock to stock quickly.

Any help is appreciated, cheers.

1 word.. Rivatuner

Totally forgot about rivatuner, didnt know it supported profiles but will redownload it to try it again.