Is there a way to switch one set of speakers between two sound systems?

This may seem nutty at first, but it's been suggested as an unorthodox solution to a tricky configuration problem.  Before dismissing it out of hand, I thought it'd be worth asking for constructive feedback on Audiogon.

Is there any way to switch a single set of speakers between two different amplifiers without compromising sonics?  Switching would be done often, so the mechanism would have to be easy -- preferably with a remote or the twist of a dial or even done automatically by sensing input signals, and definitely not involving moving cables.

If this is confusing, here's a simplified example: A listening room contains two systems, one solid-state, one with tubed components.  A single stereo speaker system has only one set of inputs.  Is there any product or configuration method that would like the speakers to seamlessly reproduce signals generated by either system.  Since the two amps would never be playing simultaneously, the speakers might merely play any signal that reaches them, like MartinLogan subs, which  automatically play any signal received at any of their three inputs.

I understand that a “simple” 2-to-1 junction box would not be so simple in an audiophile environment, especially when routing amplified signals from components that might have greatly different output-stage characteristics. 

Any ideas?