R packages for Affymetrix CDF data is now available on the Bioconductor website at: http://www.bioconductor.org/data/cdfenvs/cdfenvs.html (as well as the 'Affymetrix CDF Packages' link from the normal data page. Please contact Rafael Irizarry (rafa@jhu.edu) with questions regarding the packages themselves, and myself if you have questions or problems relating to downloading of these packages. -Jeff