Bseek
Gypsy Feet
For those of you that are do it yourselfers, check out these plans for a good old-fashioned lift top camper. We've come a long way, but it has some fairly good ideas for maximizing sleeping space.
http://www.countryplans.com/vintage_farm/metalshop/PSMay67PopUpCamper.pdf
http://www.countryplans.com/vintage_farm/metalshop/PSMay67PopUpCamper.pdf