Nokia shows off nano technology at their Mobile World Congress booth. Water is dropped on a prototype phone with a superhydrophobic coating and it slides off to a surface with graphene based sensor. This is relevant to the mobile space in that it improves the water resistance and fingerprint resistance.
Graphene is interesting because it is transparent, conductive, and stretchable. This opens up the possibilities of devices that can sense gestures like pulling and twisting. Interesting form factors can also come out of this.
No current Nokia devices have these technologies yet.