Why not let the user entering the URL select the appropriate category? That's just one less step for the admin script.
Have this input go to a MySQL table that contains unchecked links. Read that table and output it with checkboxes(or radio buttons) in which you can approve/delete the submissions for your admin module.
If you approve, move the link to a table consisting of only approved links. Use this table for displaying the links to surfers.
If not approved, delete the record. I don't think you'd want just 1 table of both approved and deleted URLS because this would get huge after time because of all the deleted urls submitted(SPAM sandwhiches).
There's probably better ways to do it though.
HTH
