I'd previously been using Curl through FFI bindings for a simple Lisp web client project of mine, but have now switched to Drakma as it's much easier to use.
However, there was one feature in Curl that I needed which was missing, and was easily added in the attached patch. Curl has an autoreferer option, which when following redirects, automatically adds a Referer header containing the URI of the page that is being redirected from. I've added an equivalent option to the http-request function.
Colin Simmonds