Nah, cryptography looks a lot better
http://www.extremetech.com/wp-content/uploads/2014/02/Code-640x353.jpg
Definitely Bitcoin. Gold is way too slow and difficult to move to have any use for trading in the age of information.
You can buy "paper" gold (yes, I know about its drawbacks and all that)...
It would still be irrelevant for commerce through the internet, wouldn't?
And central authorities would have to massively adopt this so it could be useful, I very much prefer cryptocurrencies' decentralized system.
Strictly speaking, no, it wouldn't. But there is no problem selling it at any moment, so it doesn't actually matter. And that's why central authorities don't need to "adopt this" at all, they already have fiat...
But how could someone know that the paper gold is actually legit, if it was not controlled by a trusted third party?
What do you mean? You buy gold derivatives (e.g. gold cash-settled futures) through exchanges, no one promises to deliver you physical gold...