OpenEEG is the first OSHW project we encounter back in 2004. It was developed by people all around the world connected by Internet.
The analog part of this device project is an masterpiece and soon after the project was completed, the hardware designer was hired by commercial company dealing with medical equipment which forbid him to continue the work on OpenEEG :-), so with this move if you look at OpenEEG project you will see that there is no improvement in the electronics since 2004, but this is also because there is nothing to improve.
On the net you will see tons of other EEG projects, some use 24-bit ADCs etc, but their usual problem is that they are made by people who do not understand quite well analog electronics and do not have good analog front end, so no matter how many bits your ADC is if your front end sucks you read just noise and no useful info at all. With 10-bit ADC openEEG may seems humble, but still it will beat any competitor in terms of signal quality.
From the OpenEEG project page you can see links to many software packages which can be used to capture and analyze the EEG signals.
There are experiments with MATLAB but one of most popular software remain BrianBay and OpebVIBE.
There are lot of blog posts how to setup SMT-EEG and here is interesting video on how you control motors with your eye movements and EEG-SMT :
Here is Mindball game made with OpenEEG:
EEG gives valuable bio feed back to yoga and material arts trainers as you can see if you really can put your brain in meditation and relax or you just thing that you are meditating. or to see if there is brain activity of people who are in unconsciousness.