looks nice - one thing that I am trying to do with my current TOC is to re-create the ArcIMS TOC from David Bollinger. In this one there was an option of a "toggle group" (I think it was called) where only one item was allowed on. For me I would use it for the TOC for my aerial map service, so only one year's photos can be requested. Getting more than one year is silly as they just appear on top of each other (until I work out layer based transparency sliders) and have a resource hit on the server.
ACM