[NTLDR]

OK, some cool debug stuff

Look at the bottom of each forum page, you'll see a drop down list, this contains all sorts of stuff thats added to it as PHP executes the code. Under this is a 'template usage' box, this shows all the templates that the page you are on has used, and how many times, if you see bold red ones then these are uncached templates (which is bad generally) and have caused extra queries which can normally be avoided.

Add ?showqueries=1 or ?explain=1 onto any URL and it gives an output of all the queries that have run on that page and how long each one took. Very usefull for finding sluggish queries that slow down the page load time.

The settings stuff as explained before.

And probably a bunch of other usefull things that I've forgotten