No need to mention the alt, but this is what I think they mean:
1. Zerocoin. There is a "minting" option in the wallet, that turns your GUN into zGUN... Using zero knowledge proofs that you own a certain amount of zGUN, these are all mixed into a pool of other zGUN, and when it comes time to spend it, you "withdraw" to a regular GUN address. The zGUNs have fixed denominations, much like "normal" fiat currencies, such as 1, 2, 5, 10, 20, 50, 100, 500, 1000.
That GUN in the new address will seem to have gotten GUN out of thin air, or out of the zGUN cloud or whatever it is. People will see it came from the pool, but can't prove where it originally came from. Everyone else participating in the zerocoin protocol get the same thing. There may be a transaction fee or something.
2. Masternodes. They seem to be getting popular these days, the grand daddy of them all is DASH. There are like 70 of them now. You need to somehow strike a balance between the collateral required for a node and the overall coin supply. These masternodes usually perform other functions aside from hosting a full node, such as faster transactions (that cost more), and a variation of coin obfuscation, or processing the zerocoin, and maybe even a budget system that is voted by all other masternodes. For their service, these nodes earn a percentage of the coins mined by miners, something like a 45% / 45% / 10% split between miner, node, and the budget system.
Masternodes lock up a percentage of the coins in circulation; they can not be spent as long as the nodes are operating. The result is pressure on the buy side for other people who want to run a node too, increasing the price of the coin in the process.
The number of nodes will keep increasing either until the coin supply runs out, or the ROI for running a node approaches zero percent. Dash supposedly has thousands of nodes, locking up a quarter of the total supply, costs $1m in collateral to run one, and owners earn about 20% per year on it.
Both of these would require either a hard fork, or an entirely new coin. If the same address format is retained, then a swap may be optional and people can just claim their coins using the private keys they already possess.
There are other systems out there too, such as DPoS (Delegated Proof of Stake). Those run about a hundred high powered servers, 20 that act as regular super nodes + 1 out of the other hundred chosen randomly. Each one is voted in by people who have a stake (other coin holders). It's decentralized by the stake holders, but the delegates are intentionally limited to 21, or 53, or some other odd number.
I can't give you more info as that's my understanding of it at the moment. Someone else needs to chime in, or a search should turn up something.
Very good - all interesting things to consider. Thanks for the details!
