Space saving guest room office combos

Decoist
Using a bed as seating when you don't have guests makes it easy to share your home office when you do!
Yelp
Hidden beds are a great space saving idea that allows a room to have dual purpose.
Elas Design
Having a totally coordinated colour scheme enables one function of the room to blend seamlessly with the other.
DIY Network
Choose an office desk that resembles a coffee style table and your guests will feel more at home, rather than intruding into your work place.
Houzz
Trundle beds make it easier to sleep two guests in a small office space.
Furniture Fashion
Have desk and bed combination furniture for an instant room change.
Anitalophile
Be inspired by the Japanese with space saving office/bed convertible furniture.
Houzz
When space is at a premium go for a mezzanine area for the guest bed.