Does anyone know where I might find an indication of what the programming/"software development" industry currently considers an average hourly rate for contract work?

Yes, I realize there are lots of sub-categories for software development. Some types pay a lot more than others.

I'm in negotiations with a client for an ongoing project, and we're basing too much on our own opinions. We need real numbers, but I haven't been able to find much.

There are lots of development services out there that list their rates. If there are no other options, I could always do my own survey of those sites... but that's a huge task.

Any help?