GridPP is a collaboration of particle physicists and computer scientists from the UK and CERN. They have built a distributed computing grid across the UK for particle physicists. At the moment there is a working grid across 17 UK institutions, helping to process the data from the world's largest particle accelerator, the Large Hadron Collider.
The UK Grid contributes the equivalent of almost 40,000 PCs to the worldwide LHC Computing Grid and the European Grid Infrastructure, both projects provide access to computing resources to over 20,000 researchers.
Partners:

GridPP - Thu 28 Mar 2013
GridPP30: Clouds & Impact
GridPP - Tue 12 Mar 2013
The Third Tier
EGI - Wed 15 May 2013
TF 2013 - Call for Session Proposals
iSGTW - Wed 15 May 2013
Powering climate models with grid computing
SSI - Mon 20 May 2013
Achieving unexpected goals from an ambitious social science project

UK Grid - Mon 20 May 2013
The SSI Blog - Top ten reasons to not share your code (and why you should anyway)
UK Grid - Fri 17 May 2013
The SSI Blog - The invaluable contribution of open-source software to research
GridCast - Wed 22 May 2013
A new era for the post EMI: all together for MeDIA
EGI - Wed 22 May 2013
EGI Applications Database as a community software repository