Play Music On iPhone over 2nd Computer's Speakers?

Well I've wasted an entire morning searching Google and being sent on wild goose chases in trying to find a solution to a simple problem.

I use a Mac at home and that is where my entire iTunes library is and I sync certain tracks etc to my iPhone (3G).

What I would like to do is to be able to play the music on my iPhone over my computers speakers at work (Windoze XP PC). However what I DON'T want to do is to copy all the contents of my iPhone onto my work PC, I don't need to synchronise my iPhone to that PC I merely want to be able to basically stream the music off my iPhone.

I realise I could just plug my PC speakers into the headphone socket but then I'd have to keep plugging the speakers back into my PC and that's going to get annoying very quickly!

I'm sure there used to be a way of doing this with iPod's (something like setting the iPod to manual sync, but if I try that with the iPhone iTunes just tells me it's going to wipe my iPhone and replace it with the contents of my PC's iTunes library which is completely blank so I DON'T want to do that!!!

Is there a way of doing this that doesnt involve Jailbreaking my iPhone (Not going to do that!) either through iTunes or some 3rd party software?

Not that I am aware of. You can share libraries between computers so one computer streams the music to the other without copying it, but there is no way to do this with an iPhone.

You could consider putting the music on a USB drive or a DVD and playing it from that instead.

just get a cheap 2nd set of speakers? I use earbuds at work so I don't bother others, so I'm no help.