I haven't heard of them. I did a lot of research on bike tours a few months ago (I'm going to Tuscany on a bike tour with ciclismo classico in May). Here are some centralized websites I found useful. The Bicycling World site is a huge database of tours all over the world, including the U.S.:

http://www.bicyclingworld.com/templates/default.aspx
http://www.biketour-reviews.com/