The first thing I would say to do is to download and use ATI Tray Tools and adjust the fan speed settings. Yeah it's a bit noisier, but personally, I don't find it to be annoying at all. From reading all the reports of how loud the X1x00's coolers were and hearing it for myself, I think a lot of it is blown out of proportion.
Also make sure you have good airflow going through your case. If it's messy, clean up the clutter as that also tends to make a dramatic difference in overall system temperatures.
And if you feel bold enough, take off the stock cooler, clean it off and reapply a good layer of thermal paste on it. All this should not void your warranty.
I just reapplied a layer of Artic Silver 5 on my Sapphire X1800XT and after doing all of that my card sits between 51-55C at idle and reaches a max of 63C. Yes, the aftermarkets offer better and quieter cooling but if you're adamant about keeping that warranty like me then try any or all of the above. Good luck and have fun!