We introduce a novel switching mechanism that relies on the bistability of a simple nonlinear electrical resonator which incorporates a varactor diode as its capacitive element. The switching action can be made fast and is self-contained in that no further circuitry is necessary. Unlike a flip-flop, whose state is flipped by applying a TTL pulse, this nonlinear switch can be engaged external to the circuit via magnetic, inductive or capacitive coupling; in this way, the switch becomes intrinsically touch-sensitive. Alternatively, the switching action can also be accomplished using frequency-shift-keying (FSK) modulation, which holds the promise of fast manipulation of the memory state. We demonstrate the potential application of these ideas by constructing a touch-sensitive LED lattice.