Go wireless (transmitter plugs into the headphone jack) or get one of those speaker switchers I used to see in electronics stores and I'm not even sure a switcher would work. They were used for two speaker stereo demos.
By the way, how old and what is the make and model of the receiver (or is it a HTIB)?
I want to add two outside speakers to my standard 5.1 system. There are no additional speaker connectors on my receiver. Is there a way to do this?