Yes, there are. There are a few that even pay the transaction fees earned out to miners, so you make the same estimated rewards as if you were mining solo. See my sig.
How does your pool compare to Slush's pool?
It's not my pool, I just mine there and find it good enough to recommend.
mineco uses PPLNS (pay-per-last-N-shares), a payment system where the work submitted in the last 12 hours or so is considered when splitting rewards when a block is found - on average every 24 hours at the current hashrate (without getting technical).
Slush uses a round system where only work you have done since the last block was found is considered, and it uses a formula where older work is valued less. The formula isn't good enough to make it completely hopper-proof though, the fee is 2% and they keep the earned transaction fees. They have a higher hashrate, so you get more frequent smaller payments.
ozco sounds like a deal if they are going to pay out 55BTC per round for the next several rounds though.
Here is a comparison of mining pools.
