Mitch's audio switcher should work great and it has more inputs for the future, however if you get a cheapo usb sound card you should be able to use it with the winamp line in plugin (you may have to leave it running on the background if you're not using RR). I basically do that but I use an input device that Mitch also made (basically a USB sound card with just one input). The quality and audio volume will vary based on the brand/quality of the device. Lastly you will have no volume control of that device (in RR at least), so it is basically whatever you can set (and leave configured) in the windows mixer. Awhile back I looked into trying to find some cheap 2-IN to 1-OUT audio mixers and could not find anything useful. In my previous carpc I just ran a cable to the CD-IN input of the motherboard (most computers have that) - this generally also works very well for 1 extra audio input (on the other hand, the "mic in" input is awful for music).