We're planning a trip to Vienna, Prague and Romantic Road area for September of this year. I've been to all of these places before and love them but have never been able to find zither music on previous trips. I love zither music (Third Man theme and all) and am determined to hear some this time. Who can help? Where will I find it? (Have also been to Grinzing and unable to find it there either)

I like it too and am fortunate to attend a private party every year at the Sacher where they have musicians playing this music.
I'm a little confused about the exact name of the musical instrument, but I think the Third Man music relied on "schrammel" (hope the spelling is correct).
However, your best bet might be to contact Vienna's top lady zither expert, Cornelia Mayer. She could let you know where best to hear it (or where to hear the best)...you could even take a course with her!
http://www.wiener-zither.at/site/index_e.htm

BTilke, Thank you so much. I doubt that my musical talents are up to a course but I will definitely send an e-mail to Ms. Mayer to see if she can suggest places we can go to hear her or others she thinks skilled at this wonderful instrument. I'll also plan to stop by the shop mentioned on her site where I can pick up her CD. Terrific. Thanks again.