I got some fast food the other day for lunch, and since I had two drinks, I grabbed one of those drink carriers (pictured above). I was looking at it and thinking that sometimes the best technology is the simplest technology. The carrier is made of cardboard and molded into a form that compensates for different sized drinks. Each carrier costs 17 cents in lots of 300 (in case you want to order a bunch), although the big fast food companies probably get a price break. Somehow.
Another example of simple, effective technology is the "Disturb/Do Not Disturb" hang tag found in hotels. I'm not sure who was the first to patent this idea, but they have made a bundle off it. It's one of those inventions that you look at it, smack yourself in the head and say, "Why didn't I think of that?"