Or rather, Audio in Posts.
They’re not iTunesey podcasts, yet, but they’re simple enough.
Your mp3 file must be less than 2MB and uploaded to your blog in the normal way.
Go find the menu in Dashboard–>Options–>Audio Player.
Read the check boxes, the third check box will automagically change your mp3 links in your posts to embedded flash players. Easy-peezy.
Look at wmcauley’s mp3 links.