I just came across this post on DIYDrones: http://diydrones.com/profiles/blogs/found-cheapestever-lidar-seems

Basically the company Electro-Optical sells kits and spare parts that you would need to make your own LIDAR system, This includes things like the nanosecond timer, transmitter module, receiver module, controller,  and laser diodes.

The cheapest kit runs about $430 and supposedly the boards are pretty small. Check out their site for yourself (its under construction).

http://www.eodevices.com/main_home_frameset.htm