I've started to use Ableton Live for sequencing in the group that I'm in, Monte Carlo 76. So far, we've been using the Korg nanoPad to control the scenes in a pretty basic way. Create Digital Music has a full review of the new Novation Launchpad, a grid-style MIDI controller for Live. The design is simple, but it appears that you can even control volume and other parameters by switching modes and dragging your finger up and down the columns.
Since I haven't settled on a controller for Live yet and since I see it figuring prominently into my solo music in the future, this looks promising.