There's an article on O'Reilly's OnJava right now about Servlet Best Practices. With all this talk of going back to basics (not using EJBs, using POJOs, etc.), this is a very good topic.
This article briefly covers different MVC frameworks and talks about not overloading your servlet sessions which are both pretty basic if you've been around server-side Java for any time. But the stuff I thought was interesting was an example for serving up files without the overhead of the PrintWriter for a 50% improvement in performance, which was new to me. The article also includes a nice example class for loading configuration files into servlets which is worth a gander. And also it says, don't ever use SingleThreadModel, which they say is a horrible mistake in the servlet API. I've never used it, so I guess that's good... ;-) This is good stuff to know.
Anyways, interesting reading with some neat tips or even just as a review. I'll be interested to see the next installment.