I'm considering buying this for our Syrian: http://m.zooplus.co.uk/shop/small_pets/runs_fencing/73281
She used to have a daily run around our flat every evening as I thought I had hamster proofed. Turned out I hadn't as we had a panicky 2 1/2 hours on Monday night when she had apparently discovered a hole somewhere and managed to get under the floorboards and in the walls of our (very new and modern) flat. Turns out modern flats are pretty open in their 'skeleton' and we were lucky she didn't run into any of the walls to the other flats in the building. Thankfully she came out again but we don't want to risk it again!
So I'm considering the above where she can run around in our living room in the evenings and be a bit more part of the family, get some exercise outside of the cage etc.