I use it to post urls from mail messages (which I read in Gnus). The function first loads the url in order to get the title information for the page to use in its del.icio.us description, then loads the del.icio.us posting page with the appropriate information for the url already filled in.
Don't forget to replace 'johnsu01' with your name.
(defun /john-delicious-url () "Post either the url under point or the url of the current w3m page to delicious." (interactive) (let ((w3m-async-exec nil)) (if (thing-at-point-url-at-point) (unless (eq (current-buffer) (w3m-alive-p)) (w3m-goto-url (thing-at-point-url-at-point)))) (w3m-goto-url (concat "http://del.icio.us/johnsu01?" "url=" (w3m-url-encode-string w3m-current-url) "&title=" (w3m-url-encode-string w3m-current-title)))))