As I am hearing quite frequently that you can use a nvidia GPU as a CPU. I am curios if this will work. As I understand you have to a proprietary driver. I would really like to know how to do this.

I think this is the information you are looking for.

yes ,The C compiler includes a set of C language extensions that will enable developers to write C code that targets NVIDIA's GPUs directly.

read this http://arstechnica.com/old/content/2007/02/8878.ars

Is this something that the average Linux user (non-programmer) can take advantage of?

I downloaded the software and am going to take a look. I think it will require a new build of applications to take advantage of this, but i have a lot of reading to do of stuff that may be a bit over my head.

The question is, why do you want the GPU as a CPU ? This will only help you significantly if you have a lot of GPUs hooked together.

The GPU is designed for doing graphical stuff, while the CPU is designed to do general app stuff. Unless you're doing something graphical or scientific that would benefit from a graphical point of view, there is no use in using a GPU as a CPU.

I was thinking of re-compiling a game like Urban Terror. That is graphics intensive and may benefit. There are others as well, like Torcs and Sauerbraten.

If the game uses opengl, I think there will be no real benefit.

I think you didn't get the point of running programs on the GPU.
No game will benefit from that.
Modern GPUs are highly parallel working CPUs, specialized on working on chunks of (graphical) data, like the SIMD extensions in a normal CPU. So every task that can be programmed to run in many parallel threads can benefit from running on a GPU. Examples are media-encoding, folding molecules for cancer research or simply calculating physics in games.

But you can't take any application and run it on a GPU, the application has to be written for it. And it won't speed up games, since games are specifically written to use the GPU (except the physics thing).

I haven't looked into this, but if it's anything like trying to find something applicable to run on a Cell processor, it'd be tough work. I was investigating getting a PS3 just for this, but ultimately didn't bother.

Don't get a ps3! You can no longer put operating systems on them of your choosing. I looked into this because I wanted a media hub.

Yeah, sorry - that was about 2 years ago ...