I just ordered one of the Manley Skipjacks. I stumbled apon it while looking for a way to have a home theater bypass. In other words, be able to switch the front two channels between using a high quality preamp and the front two channels of my home theater processor.
It does that, but much more. You can use it as a 4 to 1 switch, a 3 to 2 switch, a 2 to 3 switch. Cooler yet, if you want to compare two CD players, you can plug both players into the "in"s and the "out" into your preamp. It comes with a 25 foot cabled, hand held, toggle switch that lets you switch back and forth, between the sources. It will also randomly toggle between the sources. You could use it 1 to 2 for biamping. They even added a large weight inside, so heay interconnects don't pull it off of the shelf.
The folks at Manley Labs and Acoustic Sounds swear that it is totally transparent. I plan on using it 2 to 1 as a home theater bypass. It is, however, for RCA connections only.