I love Audioboo. We use it as one of the ways to publish to edutalk.cc and I've joined in tagging some boos uksm for the UK Sound Map project.

I've used the html audio tag, 'cause I am lazy older browsers will not see players in the map pin info bubbles .
Update 2011-06-25 doing a bit of feature detection and using a flash player for browsers that can't do html5 audio for mp3s. Using imlucas's gist: 341559 — Gist & jQuery.

This webpage just puts my boos on the map using the rss feed from audioboo, php to parse it using XMLParser Documentation/Tutorial google map info and code from info from Google Maps API Tutorial.
I also borrowed some css from ZURB – Super Awesome Buttons with CSS3 and RGBA and mades the shadows for the map icons with Shadowmaker.

iPad woes, I can't seem to get the audio player to work in the gMaps ballons, work ok here: