PSP Fanboy has a great “How To” on streaming music from your PC to your PSP.
Here’s very roughly what you need to do..
1. Install IIS (Internet Information Services) on your Windows PC. It’s under Add/Remove Windows Components under Add or Remove Programs on the Control Panel.
2. Install PHP 5.
3. Unzip psp_rss_1.0b.zip into your PC’s music directory.
4. Share your music folder through the “Web Sharing” tab under your music folder’s properties.
5. Make sure your user permissions on the shared folder under the security tab include the user IUSR_PC, this is IIS’s default internet guest account.
6. Go to http://youripaddress/yoursharedfolder on your PSP!
This is pretty much at your own risk, but for those who are wanting to do this, this guide is pretty straight-forward.