Speaker sharing on the cheap?

Here’s a question for my valued Gadgetbox readers. I have two desktops that I share with a USB KVM switch. For the most part it’s great, but I also want to share a set of speakers between the two of them. The options, as I see them, are to hook up a full-blown stereo receiver, where I can toggle back and forth using different inputs, or to replace my $15 USB KVM switch with a more expensive alternative like Belkin’s $40 Flip (pictured), which also lets you switch a sound input.

I’d love it if there were a cheap minijack-only A/B switch that would just let me toggle back and forth between two inputs; really, that’s all I need, but I can’t seem to find anything matching that description. Has anybody seen anything like this and could point me in the right direction?