I am thinking of installing Linux for the first time to try it out (Ubuntu probably), but I have exactly one concern:

How am I going to control my Radeon X850XT's fan speed? Normally it's stuck at 5%, and you need a fan control program (ATI Tray Tools for example, which is for windows) to make the fan spin faster. However, so far I cannot find any Linux programs that will allow me to do this.

Any ideas?

I'm not sure how u do tht...

Umm... ok... So there is absolutely NO linux program for fan control (or not fan control specifically, but fan control being a part of it - for example, many overclocking programs feature fan control).

in the standard ubuntu repositories there is nothing that ive spoted offering what you want.
However with a live cd you may notice that linux controls the fan speed automatically or that u can fiddle one of the nvidia tools to work with your ATI card,
both longshots but downloading a live cd to give them a try isnt too hard (i recomend kubuntu as it will allow more customisation)

NOOOOOOO!!!! *cries* ati fan controller needs some love out there!
I recently installed ubuntu and loving it, but it seems very limited to what Windows has to offer in terms of software availability such as ATi Tool. I wish there were as much developers as windows devs to create more home brewed software for linux. You'd think Linux was the more likely to have advanced software utilities but possibley because not enough user base or gamers on linux platform.

I hope we see some OC utilities for Linux soon