In Italy, roller shutters that block all of the light (like this) are pretty much ubiquitous. (This is one of the few things where I think Italy is less retarded than the rest of the developed world. Now I've bought a sleeping mask and I'm going to use it the next time I go abroad.)
I have often benefited from recommendations for Things I Didn't Know I Wanted.
Given that Less Wrong is a community of unusually intelligent, critical, and self-improvement-focused people, I suspect we can generate a pretty helpful thread of product recommendations — perhaps even a monthly thread of product recommendations.
Rules: