Some tents, gazebos and other temporary constructions commercially available...
http://www.fieldcandy.com/_all
Interesting tents that are available from Field Candy, based in the UK. Photo prints of various querky themes - Circus Tent, Machines, Wedge of Cheese - all sorts!
You can see how a water melon or two would fit in well at Glastonbury!
http://www.juxtapoz.com/current/tents-as-art-projects
Not too sure on the colours, but I do like the shape of this tent.
http://www.galatent.co.uk/gala-tent-star-shade.asp
I like this design - effective and looks different. Not quite what I'm looking for though - I need sides and perhaps not so tall!
I think ultimately though, tents are not practical for use in residential homes. They are not a good structure for access, have floors which are a trip hazard and are not quite right for this venture.
A project run by Clare Ford exploring the use of ipads and technology with older people.