I don't think decentralized CPPSRBP is currently possible because there'd have to be some way to manage a pool wallet for when there's a surplus from a block reward/pay from it when needed and doing this in a decentralized manner would be very difficult.
There is no wallet or surplus with CPPSRBP. The Eligius coinbases pay out to miners, not a pool wallet. There is a share log and every block that gets paid out to the most recent shares adding up to the value of the block. If the round was unlucky then not all shares from that round will be paid. If the round was lucky then some old shares will be paid. I don't know enough about the internals of p2pool to know whether this is possible.
EDIT: This isn't quite right since Eligius doesn't pay out until your balance reaches the minimum payout. Still the blocks rewards are paid directly to miners (who have accumulated a large enough balance to get paid out), not to a pool wallet.
Eligius usually pays directly using the coinbase transactions of blocks the pool mines, but from the
Eligius CPPSRB page:
When a block is found:
- Go back 25 BTC into the share log, and reward those at PPS price.
- Delete those shares from the log
- If the entire database was paid and there are still funds left, include it in the next block's reward
When a block is orphaned:
- Undelete the shares rewarded for it
I may be wrong but I don't know how BTC saved for the next block's reward could be awarded using the coinbase since the full block reward needs to go somewhere. I mine on Eligius and every once in a while I get regular payments (i.e., not "mined"/generated payouts) to my address so I just assume it was from coins the pool had to pay to itself due to a lucky streak. (or nice people donating/miners typing their address incorrectly :p )
@spooderman like kjj, smooth, and lenny_ above me said you won't be charged fees when you get paid via p2pool, but mining on p2pool with a low hashrate will lead to a bunch of tiny payments into your wallet which will cost a lot in transaction fees later on when you try to spend the coins if your wallet isn't smart about making small enough transactions which can be sent with no fee. Normal pools just wait until you have mined a certain amount before sending you a payout which leads to fewer transaction fees when you later spend the coins but I believe p2pool sends you a payout as long as you have found at least one p2pool share during a round which means a bunch of tiny transactions if you usually only find a couple of shares per round.
However you can get around this by trial and error if you're using bitcoin-qt: keep trying to send transactions and decrease the amount until it doesn't ask for a fee. You can keep paying into an address of an exchange account and then withdraw all the coins from the exchange back into your wallet in one transaction which should make spending your coins much cheaper.
(I hope the exchange wallet has an intelligent way of bundling these tiny inputs into other transactions so they aren't hit with fees!)