Music Sharing, Best Approach

We run a WHS V1, 1 PC, 2 laptops, 2 iPhones. Furthermore we have 2 iTunes accounts.

We get confused over here when it gets to sharing music amongst our devices. All our cd's are ripped and stored on the WHS. The folder is shared in the network and can be streamed. Music we download on a Windows machine (laptop, pc) is stored on the WHS as well. Then I have some music copied on my business laptop, for the moments I get out on the road. To make it even more complex, me and my wife both have an iPhone with each an iTunes account. On these phones, music is copied via iTunes, but also music is downloaded from the iTunes store. If I download a song, my wife can't reach this, as the music is stored locally.

So I am looking for a better approach for sharing and maintaining our music content. Obvious the WHS would be the best option to store it all, but how do I get along from there. When I am on the road, I would need the content locally on my laptop and/or iPhone as web sharing is not always available. Is there an easy way to share playlist for instance?

How do you guys get along with this?

Thanks, Arno