What you need is an HDMI switch box, and the latest model from Ixos comes equipped with four HDMI inputs, and one output for connecting to your TV or projector.
The Ixos XHT948 costs £300 and is HDMI 1.3a compatible, so can handle 1080p Full HD signals, and is HDCP compliant. It can also be integrated into Crestron and other multiroom control systems via its RS-232 control port, has input LEDs to show which component in the system is providing the signal and a data error LED alerts the user if there is a signal failure.
If you intend to run 1080p video over longer runs of HDMI cable, Ixos has fitted its own Active iVEC signal enhancement technology which it claims increases cable transmission capability for high-definition signals.
"A 1080p signal can only be transmitted 4-5 metres on a standard HDMI cable," claims Ixos. "Active iVEC increases the distance to 25 metres, and if used with Ixos XHT658 cable, the distance is increased to 40 metres."
A mounting bracket and remote control for the unit are included as standard.