First install newest NVIDIA driver. 'nvidia-experimental-310' from ppa was good for my laptop's GT220M. For desktop's GTX550Ti I needed to install driver manualy from nvidia.com. Next step is to download CUDA pack from
developer.nvidia.com, and latest PyCUDA and PyOpenCL from
https://pypi.python.org/pypi/pycuda and
https://pypi.python.org/pypi/pyopencl respectively.