SecGuru has posted a cheat sheet for Web Application Security. There is also an earlier version of the cheat sheet as well.

This is a handy reference, but it is good to keep in mind that no book, or article about security is ever exaustive or conclusive.

A few weeks ago I started working on an Apache Cheat Sheet - I think covers the most common configuration, let me know if you want to see anything else on there.

Looking for more cheat sheets? check out my cheat sheet roundup.