Embed media confusion? Exist on one WP 3.1 site and not my other

So I read the “Troubleshooting WordPress 3.1 – Master List” and saw the section about embedding media.

And the website it referred to, http://wordpress.org/Embeds doesn’t exist.

Here’s what I don’t understand. The site I just made doesn’t have the “edit/embed media” button in the kitchen sink/dashboard.

However, the wordpress site I manage at work (also 3.1) has an “edit/embed” media in the kitchen sink/dashboard.

So…. how the heck do I embed media within a page?