If you don't want to wait for a "special" rotary switch, you can always get two DPDT switches from Radio Shack and cascade them;  a little funky but it would work in you have 3 inputs.

i.e.

switch A switches between input#1 and switch B (for additional choices)
    when switch A set to position switch B
    use switch B to select between input #2 or input #3