I've been using DotTunes for years now to access my home iTunes library remotely and been very happy with it despite the fact that it was orphaned long ago. Well, Lion finally broke it and I've been searching for an alternative since - Googling "stream iTunes over the internet" turns up many many blog entries describing all sorts of arcane steps to setting up an SSH tunnel and advertising the Bonjour service. I spent most of today trying to get that to work and spent a few dollars on SSH front-ends as well, but ultimately cound not get it to work. Then I noticed that all the hits I was getting on google were from like 2004-2008 and I figured I needed some different search criteria. Finally I stumbled on Sharetool on the second page of hits from a google search on "itunes sharing via wan". The purchase price was not an issue since it looks like you are serious about supporting the app (unlike a lot of developers these days who are just out to make a quick buck and who can't even be bothered to write documentation). Setup was easy once I removed some duplicate port forwarding that was in place after all my previous mucking about.
I have my music at work again, yay! Long Live ShareTool!