This seems like it should be easy but I'm having problems with it. I need to retrieve a vector (the pointing direction) from an angle around a given axis. I can retrieve the quaternion using fromAngleAxis, but then how do I get the vector? Or just get the vector directly from the angle and axis?

Quaternion quat = new Quaternion();
quat.fromAngleAxis( FastMath.PI * angle / 180 , new Vector3f(0,1,0) );

Remember that quaternions are not absolute "directions"in a space. They are relative rotations, so you will always need the reference (Y-up or similar).