The date – template hacks?

So I posted this in plugins and hacks and dont think I posted it in the right area…

So on Matt Mullenwegs blog he has it set up so that ever post he does doesn’t show you the date of the post unless you click on the on the blog entry its self, and you only see the date posted on the front page if you are looking at photos he posted or “major” blog posts where theirs a banner and all.

I am wondering how to do something similar show the date of the post only when I want on the front page.