Here is a list with five other companies:

http://www.nvidia.com/object/gpu-cloud-computing-services.ht...

Thanks for pointing it out. I should have known better considering that I am in the space :(

Interesting - thanks! Are any of those plans more reasonably priced than Amazon's?

Hmm, Amazon now charges $0.65 per hour for their g2.2xlarge GPU plan (in Linux). See http://aws.amazon.com/ec2/pricing/

I checked spot instances just now, and it was less than $0.10 an hour. So for batch jobs that might be an option. And if you're using it interactively, than you can always go EBS backed and just turn it off when you're done.