Summary data tables for V-band differential photometry can be found from this page. Please see the README for an explanation of the data presented (also see arXiv:0912.3621). Full-resolution flux-calibrated spectra can be found from the links for individual objects or from http://james.as.arizona.edu/~psmith/Fermi/DATA/specdata.html.
R-band differential photometry is also available. Broad-band photometry in B and I is more problematic as the spectra do not entirely cover these filter bandpasses.
Please contact Paul Smith (email@example.com) if you have questions concerning these web pages.