Thank you both. I know what I'm going to do then. Rather than get lost in Podcast World, I'll put together a short programme to run on my page. I can then take advantage of the opportunity to welcome those who have dropped in for a visit, get out any other messages I want and play a little music. Ten or fifteen minutes should do the trick and it won't come on unless the guest invites it.
My only real question concerning this would be "How long can it be without creating problems for the server or visitors? and Is there a file format that would be more user friendly than MP3?