We had a thread about Solexx and Ken shared his thoughts on that. It would definitely solve your problem of bringing light in while not showing to the outside what the contents are. It's like a milk jug.
I'm still in the design phase of my own greenhouse and I'm going to build a so-called "solar greenhouse". It is solid walls on 3 sides and the 4th side which faces south is the only wall that is plastic or glass. The south wall is inclined in a manner that maximizes solar exposure during the coldest months which, for me, is about a 55 degree angle.
