Here's a simple way to check all md5's of the files in the current directory.
You can store them and check them daily or whatever do with the output
you might find handy...(yes i know this can be done differently..but I cant help it ;-)
(silent (map (fn(x) (println (crypto:md5 (read-file x)) " - " x)) (clean directory? (directory))))
PS: (load "/usr/share/newlisp/modules/crypto.lsp")
PPS: checking remote content is a nice way too.
Enjoy..