download_Rcpp_releases <- function(){
    # download archived versions
    url <- "http://cran.r-project.org/src/contrib/Archive/Rcpp/"
    rx <- '^.*(Rcpp_.*?gz).*?right">([^\\s>]*?)\\s.*?right">\\s?([^>]*?)<.*$'
    lines <- readLines( url )
    archives <- gsub( rx, "\\1", grep( rx, lines, value = TRUE) )
    sapply( archives, function(.) download.file(sprintf( "%s%s" , url, .),.) )

    # download the last version
    download.file(
        "http://cran.r-project.org/src/contrib/Rcpp_0.8.9.tar.gz",
        "Rcpp_0.8.9.tar.gz" )

    invisible(NULL)
}