First open the synaptic package manager, and install all the fglrx packages, including development. Also download boost, boost-dev, g++ or gcc for c++, and subversion. Now, go to http://forums.amd.com/forum/messageview.cfm?catid=390&threadid=125792&enterthread=y
and download the packages i386 or amd64 depending on what architecture you are using, and the dev package too. The ubuntu package manager will say some crap about them being unsupported, just force install them.
Now go to http://pypi.python.org/pypi/pyopencl/0.92
, download the tar, unpack, and do the usual make and make install.
Then go to a terminal and execute these commands
svn checkout http://svn.json-rpc.org/trunk/python-jsonrpc
sudo python setup.py install
And finally, download the poclbm "source", all the files, drop them in a folder, and change poclbm.py to executable.
Open a terminal, go to the folder where you dropped the files, and type
./poclbm.py -u yourusername --pass=yourpassword -d 0 -o yourminingpoolurl -p 8332 -f 60
Then be happy about all the time you wasted to get 2 more mh/s.