Kristin indicated aviary.com may not be serving educators for much longer (I see aviary education.com is no longer accepting registrations), I decided to try podcast hosting elsewhere. Evidently, it was once possible to host podcasts on Blogger, but that seems to have been discontinued.
Dropbox works. On my very much under construction teacher blog which uses WordPress, I just added a link to my podcast hosted on Dropbox, and it just worked. I use the same method (an HTML anchor) for Blogger:
BTW, here's how I created my podcast. I recorded an audio track using QuickTime Pro. I grabbed some music from ccMixter, a Creative Commons-friendly site. I installed the free Audacity app, and used it to fade in/fade out the music track from ccMixter. Then I just pasted it the music and my voice recording together in QuickTime Pro, exported to MP3 format, and dropped the MP3 into Dropbox.