I haven't been able to find information on how to efficiently index UTXOs. Can you explain or point me to some resources?
Update: Btw, I understand completely that the notion of address balance is awkward at best, and that it can never really be known with 100% confidence, especially as P2SH transactions gain popularity.
@PieterWuille to query balances for addresses. – stanm87 Oct 09 '14 at 11:38