I'm posting this here in Development because the developers usually are more interested in this kind of stuff. I'm not 100% off topic because I have a project I'm working on that controls a custom Arduino board (on PCB made like this) with the N900.

The community I'm part of has a custom PCB order that goes out every 2 weeks.
The cost it's $5 per square inch for three copies of your design. So, a 2 square inch design would cost $10, and you'll get three copies of your board. Shipping by US Mail is included, and there are no setup fees. Your boards will be mailed within 9 days of the order deadline.

Here is the link:
http://dorkbotpdx.org/wiki/pcb_order

and here are some pictures with the custom boards like they returned from the fab house:
http://www.flickr.com/photos/laen/4013181884/

Edit:
here is one of the PCB I got and I'm working on:
http://lh4.ggpht.com/_wyAZ3sieWE4/S_...100526_005.jpg