I know there were questions as well as problems that people had regarding streaming .mp3 files over the web on their Pre. Well thanks to .plaid at everything Pre we were able to figure out that as long as the mp3 is hosted and linked directly to (http://domain.com/filegoeshere.mp3) then you can direct your Pre's browser to it and stream it. What's great is that this also has a sliding selection bar like the iPhone's, which implies that we might be able to get this feature on the integrated Music Player app. Anyways, for how to do all this in detail, go here: MP3 Streaming Possible On Palm Pre With Hosted .mp3 Files | Pre Insiders

I know that some people know how to do this already, but I searched and there wasn't really a definitive guide and I know some people had questions about it. Just making the information more available, as when I searched on the forums nothing came up.

Enjoy + leave a comment if it helped at all