Check this out. It works!
http://www.g4techtv.com/screensavers/features/47977/Overclock_Your_Video_Card.html
It very well may work, but those warnings SHOULD NOT be tossed aside lightly. Overclocking ANYTHING in your computer is essentially signing a commitment to it, saying "I will vaccuum you out REGULARLY, and make absolutly sure that nothing every blocks your air INTAKE or OUTAKE!" Most people end up investing in a better fan than a stock one.
Best of Luck!
Of course you need to take the precautions needed to do it, but I went through and did the Nvidia set and it works superbly.
I ordered a new fan last night and will put that in. I clean my CPU out once a week anyway, so no fear there.