I like Ric²

But right know I don't know how to make it more RAM demanding... (that is, without radically changing the PoW). After seeing the alleged speed of primecoin's gpu miner, I think that a Ric gpu miner will eventually be unavoidable. Newer GPUs will keep getting more and faster RAM anyway.

I was thinking of making the nonce (offset in the block's header) be 512 bits long instead of 256. This would allow for more efficient mining putting us closer to the elusive world record.

Also 5 mins per block: the wallet would sync faster and each block would have more difficulty, getting us closer to that record....