Anyone know of a php script to extract files from a zip file.

I doing a little photos album application and I'd like my, non-techie, users to be able to zip together their photos and upload them to a folder on the site. I've got everything going nicely except the unzipper. I would not like to teach them to use ftp, even with a browser. I'm on a virtual host that doesn't have the ZZIPLIB. Thanks....