PowerA's MOGA Mobile Gaming System for Android devices was a neat idea that must have done reasonably well for itself. The company has announced a new model at CES called the MOGA Pro which more closely resembles the standard design of console controllers.
Available this spring, the MOGA Pro offers the same functionality as its predecessor: Bluetooth support for Android phones and tablets, the MOBA Pivot app, and the extendable arm that secures your phone. While less portable than the original controller, I don't know how much of a concern that was, anyway. This seems like the perfect thing to bring on an airplane.