Thanks for the link, Fallen. I was actually considering trying out a recipe using the herb tarragon, which the author probably wouldn't recommend. Sounds weird, yes, but there is an Armenian tarragon soda that's actually really good so I think it may work. I've made a decent raspberry cordial before and also an interesting cardamom/clove blend that some friends of mine swore was great mixed with Coke.
Here is the link to the company that made the machine. It appears to have been discontinued as no mention is made of it.
http://www.donvier.com/donvier/