Synth Site |  Emu |  Launchpad

You connect the Launchpad inline between your keyboard and the rest of your setup (it merges its MIDI In into its Out), and it gives you a goodly number of things assignable to any MIDI control: 5 sliders, 1 button, 1 footswitch input, and 1 proportional pedal input (voltage or resistance). You also get a pitch wheel, increment/decrement buttons to switch songs, banks, and programs (though the bank option doesn't work right), a really hokey MIDI Beat Clock feature, 13 wretched transposable velocity-sensitive "drum pads", and a bank of 6 buttons that can be in either "transport mode" (sending MMC/Sequencer Control SysEx) or "trigger mode" (locking on notes to play background pads or rhythms, assignable to any note and channel).

The Launchpad does what it does quite well. E-mu could have put a lot more effort into the "drum pads" - they *really* suck. And it should be cheaper. Other than that, it's a great niche product.