Family Force 5 uses a Keywall. You can see it in there if you watch closely.
Though they also have "conventional" keytars:
An absolutely insane band--and the one that first proved to me that Christian Bands didn't have to sound like condensed yawns.
Incidentally, the Keywall (a.k.a. Family Force 5000) was made by David Crowder Band's drummer. Which probably goes some way to tell you why I like David Crowder so much as well.