wget would definitely give you what you want (if you just want html/css/images.) I don't believe wget is available on a base Tiger or Leopard install, so you'll likely need to build it on your own, or use macports/fink to get a copy. Anyway, wget will fetch recursively if you tell it to. My only suggestion is that you use the --wait option, to specify how long you wait between requests, so that you don't hammer any sites with requests.
Use it like this (from the terminal, obviously):
wget --wait=5 -r -p
http://url.tld