Main R archives lost "packages" directory - don't copy to your mirror site
cran.r-project.org
cran.r-project.org
http://cran.r-project.org/web/packages
This change is propagating to the mirror websites. For some it might mean downtime with their statistical analysis.
EDIT: Actually, you can still get the packages source code here:
http://cran.r-project.org/src/contrib/
Binaries for mac os x are here:
http://cran.r-project.org/bin/macosx/leopard/contrib/
But I don't know where to get the PDF documentation for the individual packages.
EDIT2: Google keeps cached PDFs, you can view them using Google docs pdf reader.
P.S. I've contacted Uwe, Kurt, and Stefan but probably they are already gone for the day.
Also most pdfs for R packages will show up in a google search somewhere.