Problem
Analysis of Particle Physics data
Scale of accelerators & detectors means only a few sites
So large collaboration (hundreds to thousands) of physicists from tens to hundreds of sites in tens of countries
Create large data sets with hundreds of Terabytes to Petabytes of data over the next decade
Some sites already taking data (Jlab, SLAC), some will turn on soon (FNAL), LHC at CERN data taking in 2005, creating simulation data today