To save a web page with the wayback machine, append its URL to http://web.archive.org/save/ and GET the resulting URL.

I have two archive.org webjumps for the conkeror browser:

  define_webjump("wayback", "http://web.archive.org/*/%s");
  define_webjump("wbsave", function(url) { return "http://web.archive.org/save/"+url; } );