Real-Time Multiplayer On Mobile

This is obviously a very broad topic and one that is gaining popularity. I was hoping to start a discussion on techniques for dealing with things like packet reliability, latency, bandwidth limitations, and the seeming constant variability in all of this. Also, with battery life being so important, are there per frame techniques for saving power to give the player the longest play session possible?

With phones becoming more and more powerful, how close are we starting to get to matchmaking the power and reliability of a low end PC?