Like Tom I also have chosen the Home Brew route.
They are suprisingly easy to build not difficult at all. Little soldering, little drilling.
I have two units that I have built, One is a 4 meg pixel still camera that is modified for Infrared (IR) with a slave flash. It has batteries and memory sufficient to stay out for months and will hold 2-300 shots easily.
The second is a video camera also modified for IR. I have it set for 30 sec record per event. That cam will fill a 2 hour tape in a couple weeks.
I chose to use IR for the stealth ability, I never know who is prowling around and I believe its easier on the bigger bucks who tend to be a little spookier.
For those wishing to learn more about the home brew's here is a couple links to some forums that these guys hang out at. Good bunch and lots of help and advice.
Real Deal
and
Hags House
My sig has links to a few short takes from the video cam