Inserting custom fields into new-post.php without using the Custom Fields Template plugin?

Question

I know there are a few plugins (Custom Fields Template seems to be the most popular one) that lets me insert custom fields into the new-post.php template. But I'm wondering if I can add in a few fields without using a plugin -- just as a mock-up. Do I have to go into the core?

Answer 1

This article will get you there: http://andrewferguson.net/2008/09/26/using-add_meta_box/