Tonight I acquired a Korg Nanopad midi drum pad while at Guitar Center (I actually only went in to look at 4 track recorders, walked out with plenty of cables, a Boss BR-900CD recorder, and the previously mentioned Nanopad). I made sure of the return policy on the Nanopad, since I really hate buying gadgets only to find out they either don't work with Linux or work with more coercion required than I am willing to spend.
Luckily, I plugged this little guy in, and it was immediately detected by the kernel, and showed up in lsmod as Bus 006 Device 002: ID 0944:010e KORG, Inc. I usually then Google the USB ID to see if anything might come up, but nothing interesting did. I was hoping there'd be software in the Ubuntu repos that might work with this, as I was feeling particularly stoked about compiling or packaging something myself.
A quick apt-cache search midi drum yielded some candidates. I installed the first one, Hydrogen. I'd played with it before, but didn't find it particularly compelling. I started it up and started hitting the pads on the Nanopad. Nothing. Of course it wouldn't be that easy. So I went to File->Preferences, clicked on the "Midi System" tab, and, as an option to "Input", I saw "nanoPAD MIDI 1". After selecting that, I was making beats.
Linux has come a LONG way.