Velux solar hot water system
 

I was at the Home Show in Toronto and I saw a SDHW system made by Velux. They make skylights, so the collector is made in a skylight frame. The flat plate collector is black and I think it would look pretty much like a skylight on a roof. I think this could make solar hot water more palitable to those people who don't want evacuated tubes or giant flat plates on thier roofs. They looked like they were high quality.

German site

velux.de