When a passenger steps forward to get on a flight, an agent could hold up the boarding pass and passport in front of their smart glasses, scanning barcodes on the two documents simultaneously.

BBC: Could Google Glass ease air travel?

"If you get the contract right, if you're absolutely up front with both sides, you could advertise privately, but then you can also work through an estate agent as well, " advises Kate Faulkner of the website Propertychecklists.

BBC: Selling your own house: Could it save you a fortune?