NERSC allows read-only access to selected NGF datasets through OpenDAP. This is a good solution for alllowing remote access to large NetCDF and HDF5 datasets that are on NERSC filesytems. OpenDAPis an API through which the sub-seection requested is part of a URL which is processed on the webserver delivering only the subset of the data requested. Additionally the data may be processed on the server through GrADS expressions in the URL. Some examples are given below.
OpenDAP for NetCDF: http://portal.nersc.gov/
You can also look at fully worked examples of OpenDAP technology in use at science gateways such as the 20th Century Re-analysis Project.
OpenDAP is a work in progress. The Hyrax software has pursued some new ideas for what OpenDAP might do in the 2011 Google Summer of Code.