What shall we develop first: an open source particle image velocimetry system, based on OpenPIV (open source PIV software, http://www.openpiv.net), open source micro-controller and LED light or an open source three-dimensional particle tracking velocimetry, based on the ETH Zurich 3D-PTV software, or a single-camera FPGA based real-time processing (http://3dptv.github.com)?
http://www.openpiv.net