Essentially, you can use it as an n-channel crossfader. Examples include the A-144 MC above, the RxMx, or the Mixiplexer.
Right now, you could hack together a wavetable oscillator by using one Sample Player per waveform and using a bunch of these to crossfade between each player. You would set them up so that as they receive a shared voltage, only one Bump would be prominent at a time. The outputs of each Bump Map would control a VCA after each Sample Player, and the Sample Player outputs would feed a single mixer.
You could also hack together a quad panner using the same idea, but each VCA would have a separate channel output instead of being mixed together. You would also feed the four VCAs one shared input instead of four different inputs.