My husband went to Ikea yesterday and bought plastic place mats for Vingdragån. 12 of them! Yes, a hamster needs plastic place mats - they make for great walls in an indoor enclosure for them! Hubby bought these: http://www.ikea.com/gb/en/catalog/products/80311244/
And Vingdragån had his first outing there last night. It's been hot the last few days with temps at +30 C, so I also finally got around to providing him with a sand bath. He was confused at first, but started digging in the sand eventually.
Easy to build with a little bit of tape and provides lots of room that the hamster can't escape from! I can leave him alone in there. :-)
And very very easy to store when not in use!!
A little video of Vingdragån's first encounter with sand: