http://developer.android.com/training/efficient-downloads/efficient-network-access.htmlOptimising power usage on mobile devices means understanding the UMTS protocol state machine. Go learn!
(btw, we should think about this when doing p2p protocol upgrades and writing client code. bitcoinj pings nodes rather inefficiently today as part of trying to discover overloaded nodes, as the single threaded nature of Satoshi's code means responsiveness can vary wildly. but that's redundant after doing the initial chain catchup).
