Installing PyCUDA on Debian
These instructions were written for Debian Linux. You may also look at the generic instructions if this isn't working out or you'd like to install manually. ../Ubuntu generally is very similar to Debian, so those instructions might work, too.
Debian Wheezy, which should become Debian stable in late 2012, contains PyCUDA packages in version 2012.1. Currently there is no Python 3 package, so there is only Python 2 pacakges (python-pycuda) and documentation (python-pycuda-doc). PyCUDA packages are in section contrib; although they are free software, they depend on non-free NVIDIA software.