It would be interesting to have a "PoW zap". You can game Bitcoin zaps by zapping yourself, but Proof of Work costs the same either way. If clients periodically PoW zapped the accounts they follow, legitimate accounts would accumulate huge sums over time, and spammers would always start very low. On a cell phone? No problem! Someone could run a PoW zapping server that converts Bitcoin into PoW with server efficiency

Sorry, i dont follow....at all. What do you mean by 'spam it either for value or for DoSing honest updates'. Also its funny to me you talk about PoW because any PoW idea is absolute shit

Bit rude perhaps not to clarify, since you are still a PoW believer: PoW gives you no defensive advantage whatshowever. This is why it is usefull in Bitcoin, because no participant should have any structural advantage; but when it comes to protecting my stuff, i do want asymmetry, and as much of it that i can possibly get. The best example of asymmetrical defensive advantage: cryptographic keypairs. Hope this helps