A few weeks ago I made a quick App Engine site for adding links to audio files to a list, which you could then subscribe to as an RSS podcast (being the easiest way to get random MP3 files onto an iPhone). Now Jeremy Keith has done this *properly*, with Huffduffer, a superbly designed site with a simple purpose (making a podcast of found sounds, and subscribing to other people's).
Huffduffer is hotlinking the audio files, while missing Webjay's "via" field for a link to the original blog post/web page where the audio file was found, but you can put links in the description field - which seems good enough.