(use uri-common intarweb http-client)

(call-with-response
 (make-request uri: (uri-reference "http://call-cc.org/"))
 void
 (lambda (resp)
   (let ((len (header-value 'content-length (response-headers resp))))
     (print "reading " len " bytes")
     (print (read-string len (response-port resp))))))