A few folks including my self have bought the Mini ITX mother boards. They are really small and some cpu's are in the 1 to 1.8 ghz range. You can get an adapter to hook it up to an onboard 12 volt battery. They come with about any kinda I/O ports you would need. DJ has a video up in the videos section about one he got from ebay for $100 bucks. Now with auto connect and auto load of project files you can have your robot online asap.

I will be using what jstarne1 Josh mentioned in this thread:

Mini ITX

Yup AMD mini itx boards support up to 8 gig ram and sport the E350 dual core amd cpu and also draws very low power.

A couple weeks back newegg had a nice dual-core mini itx with 8gb of ram for $69.95, i've been using this on my robot and it's been rock solid. Keep checking with newegg as they have lots of nice deals lately..

@charleybot. -see another happy customer which model did you pick up? Link or pics

This is the one I got a few weeks back when they had a sale on it: http://www.newegg.com/Product/Product.aspx?Item=N82E16813138365

It's a Biostar A68i-350, it runs really good with windows8 on it and I haven't had any issues with it. It also came with a $10.00 rebate when I purchased it..

I'm starting to think that maybe I don't need two 12v 7a batterys on my robot, I am getting over 11 hours on a single charge...

Once your robot is moving , sensors scanning , EZ cam running and servos moving if you have anything else moving it adds up quick. Funny thing is the motherboard probably draws less than all the other electronics.