Korg Monotron ($60)
Although easily mistaken for a toy, the Korg Monotron is a synth worth considering if you like quirky sounds and are willing to suspend disbelief. It''s a pocket-sized analog synth that runs on AAA batteries and has a tiny built-in speaker—perfect for clearing the seats in your row on a crowded flight or, after plugging in headphones, ignoring your seatmates. It packs a switch, five knobs, and a ribbon strip with keyboard graphic, which you can play with your fingers or a plastic stylus. The ribbon shows 16 keys, but the range is adjustable.
The Monotron sports a sawtooth oscillator, 2-pole resonant lowpass filter, and a sawtooth LFO that can modulate either. Best of all, an audio input lets you apply the filter to external audio, and the results are especially interesting when you crank the resonance and run the LFO in the audio frequency range. As reviewer Gino Robair suggests, point the 1-inch speaker at your mouth and you have the cheapest talkbox on the planet. And like the Gaia, it''s a winner here because of its great sound.