PHP program to download sites

HI All, I have a client who wants to be able to download/cache all web files on certain sites for archiving info (i.e. before purchases, anything where a record of what exactly was on a certain page is needed). They would like to have this on the web server so employees could log in and enter the sites for caching and then it can have a cron job and do this at night. Is there an OS program that will take a url and crawl/cache all the links on it? If so I can easily create the interface, job queuing, and chron job setup. Thanks, -- Leonard Burton, N9URK http://www.jiffyslides.com service@jiffyslides.com leonardburton@gmail.com "The prolonged evacuation would have dramatically affected the survivability of the occupants."