hacks we should know about

hi i found it very helpful to know about hacks such as the below list and was wondering if anyone had any more dumb mistakes they could tell us before we make them. 1. http://www.somesite.com/source.php3?url=/etc/passwd 2. http://www.somesite.com?page=../../../../etc/passwd 3. not setting .inc files to be parsed by php 4. setting directory ownership to nobody _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com