SimplifyMedia: share iTunes with anyone, anywhere

SimplifyMedia is the mother of all iTunes sharing plugins, now in public beta:

Simplify Media is free software that lets you access your music and your friends' music over the internet using iTunes. There are a number of existing solutions that offer music streaming, but Simplify Media has some unique differences:

1) Within iTunes: Instead of using a limited, browser-based player, you can sort, search and play remote libraries right inside the standard iTunes UI. This is very similar to iTunes LAN sharing but the computers can be anywhere instead of only on the same subnet.

2) Easy setup: No need to upload files to a website. No port-forwarding or firewall configuration. You can have access to a multi-thousand song library in minutes.

3) Cross platform/format: Supports mp3, aac, and wma files across both Macs and PCs (Windows XP or Mac OS 10.4x). For your own account you can even access your iTunes-purchased songs.

4) Private groups: Computer-to-computer streams are encrypted, and there are limits on the number of friends you can connect to. However, despite the security, adding a user is as simple as adding a buddy in IM.

Link

(Thanks, Paul!)