XSPF Web Music Player is a streaming MP3 player written in Flash which you can embed on your website. It’s completely free to use, and while not as feature-packed as commercial offerings – it’s only at version 0.2 currently -it does the job well.
It works well with Webjay, a service which allows users to share playlists of streaming music culled from various sources.
On a related note, I feel I’m beginning to outgrow Blogger, and would like to move to something more customisable. I’m using a slightly tweaked standard Blogger template, which means my blog looks like so many others, and would like to build something like this into it (on an opt-in basis – I’m not going to blast you with music as soon as you type my URL). So keep an eye out for changes in the near future!