Many of us have heard, seen or been in the Tiny hotel rooms of Japan. They are basically just a 10x5x5 cube that you can rent for $45, which is a steal for Japan. I found this Tiny Hotel to me a bit more aesthetically pleasing. This is a single room in Germany.
I have once been in one similar in Austria, it was amazingly comfortable and had its own bathroom and shower! A little tip for when you are traveling and trying to save a a few Euros; The bathroom is considered a luxury and you can ask if they have rooms without bathrooms, this will save you about 10 to 25 Euros! The downside is of course that you have to shave a bathroom down the hall, but its worth it. Of course there are hostels too, which I highly recommend, but do your research. Anyway, back to the Tiny Hotel, check out this room and compare it to one you would find in America.