#1 Here is my system configuration [1]

javier@delfin:~$ cat /etc/apt/apt.conf.d/70debconf
DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt || true";};
APT::Default-Release "testing";

deb http://security.debian.org/ squeeze/updates main
deb-src http://security.debian.org/ squeeze/updates main


#2 Install NVIDIA drivers [2]

root@dorado:~#aptitude install module-assistant
root@dorado:~#aptitude install nvidia-kernel-common
root@dorado:~#aptitude install build-essential
root@dorado:~#aptitude install nvidia-kernel-dkms
root@dorado:~#m-a auto-install nvidia-kernel${VERSION}-source
root@dorado:~#aptitude install nvidia-glx${VERSION}
root@dorado:~#aptitude install nvidia-xconfig
root@dorado:~#nvidia-xconfig
root@dorado:~#aptitude install nvidia-settings
root@dorado:~#reboot


#3 Instal NVIDIA CUDA Toolkit and OpenCL development files

Installing:

aptitude install nvidia-cuda-toolkit
aptitude install nvidia-opencl-icd


Packages status:

root@orca:~# aptitude search opencl | grep nvidia
i A nvidia-libopencl1 - NVIDIA OpenCL library
p nvidia-libopencl1-ia32 - NVIDIA OpenCL 32-bit library
i A nvidia-opencl-common - NVIDIA OpenCL driver
i A nvidia-opencl-dev - NVIDIA OpenCL development files
i nvidia-opencl-icd - NVIDIA OpenCL ICD
p nvidia-opencl-icd-ia32 - NVIDIA OpenCL ICD (32-bit)
root@orca:~# aptitude search cuda | grep nvidia
p boinc-nvidia-cuda - metapackage for CUDA-savvy BOINC client an
i A nvidia-cuda-dev - NVIDIA CUDA development files
i A nvidia-cuda-doc - NVIDIA CUDA and OpenCL documentation
i A nvidia-cuda-gdb - NVIDIA CUDA GDB
i nvidia-cuda-toolkit - NVIDIA CUDA toolkit


#4 OpenCL headers [3]

There is a problem with OpenCL headers in Debian (it may be solved soon). Just downgrade the headers:

cd /usr/include/CL/
mkdir 1.2
mv cl.hpp ./1.2/
mv *.h ./1.2/
wget http://www.khronos.org/registry/cl/api/1.1/cl.hpp
wget http://www.khronos.org/registry/cl/api/1.1/opencl.h
wget http://www.khronos.org/registry/cl/api/1.1/cl_platform.h
wget http://www.khronos.org/registry/cl/api/1.1/cl.h
wget http://www.khronos.org/registry/cl/api/1.1/cl_ext.h
wget http://www.khronos.org/registry/cl/api/1.1/cl_d3d10.h
wget http://www.khronos.org/registry/cl/api/1.1/cl_gl.h
wget http://www.khronos.org/registry/cl/api/1.1/cl_gl_ext.h


References
[1] Debian Wiki for apt configuration: http://wiki.debian.org/AptConf
[2] Debian Wiki for NVIDIA drivers: http://wiki.debian.org/NvidiaGraphicsDrivers
[3] OpenCL headrs: http://www.khronos.org/registry/cl/