There's no doubt about it, lots of us just don't have room for an extra guest bedroom in our house. When friends and family come to stay with us, we sometimes put them in the kids room, our beds, or sleeping bags on the floor.
There's a better solution, though! A double air bed!
Married couples often sleep better together than in a child's twin bed, because a double bed is what they're used to. Surprisingly, air mattresses are often more comfortable than futons or the dreaded sofa bed with the uncomfortable bar you feel on your back every time you roll over during the night.
A double air bed fits standard double size sheets and you can get them to be low to the floor, or elevated, as if they were on a box spring. (These are more the size and height of a typical double bed.)
One of the things I really like about the air mattress I have is that it is really easy to inflate. You just plug it in and press a button and in less than 2 minutes, the whole thing is inflated and ready to go. I can put it in the middle of the living room floor for guests to use at night, and then deflate it (again, with the push of a button) and store it during the day, so we have use of all the space in our house! I've used it for my sister, my mother in law, and my fiancee. No one had any complaints. Also, my 2-year old son loves romping on it, but that probably doesn't count.