ENS stands for Ethereum Name Service and it is a decentralized domain name system built on the Ethereum blockchain. You can get domains with the .eth extension by going here, connecting a wallet, and searching and purchasing a domain.
I have purchased fredwilson.eth and avc.eth and a bunch of other .eth domains for my family. It does not cost a lot of ETH to register a domain, but you need to remember to go back and renew it as there is no company/registrar operating a business to do that for you.
An interesting angle on ENS is that the .xyz extensions are interoperable with ENS and that is explained here.
So if you own .xyz domains, you can participate in the ENS system. I also bought fredwilson.xyz and avc.xyz and a bunch of other .xyz domains for my family.
It is interesting to me to see blockchains and smart contracts being used to replicate many of the things we use to build applications on the Internet. Slowly but surely a decentralized infrastructure that mirrors the centralized infrastructure is getting built out.
While there aren’t a lot of things you can do with a ENS domain today, I expect that there will be a lot of things you can do with one in the future. And that is why I think it is a good idea to purchase ENS domains for the ones you own in the .com world.