Optical input double adaptor?

May be a stupid question but is it possibility to get some form of double adaptor so that i can have 2 optical cables connecting to a single optical input point on my DAC? I would obviously only feed a signal through one cable at any one time.
Radio Shack has them
No idea how well they work but amazon.com has lots of options, both 2-1 adapters and switchboxes. Search for 'optical splitter.'
How do you think it might affect the sound? Cant be good.
I am not certain that a "splitter" will work in this combining application and would feel more secure with a switch.