This picture of Vitalik has been going viral. We're going to let you figure out why... 

This literally caused the price of Ethereum to increase. Meme and parody accounts were, as you can imagine, having a field day. 

This picture was taken at ETHMexico where Vitalik gave a speech earlier this week. The title of his talk was "Ideas for things worth building". You can watch the full 30-minute  talk here but if you want the Cliffs Notes, here they are:

The Merge and further improvements to scalability are going to make transactions on the Ethereum network much, much cheaper. In light of that, Vitalik asks you to think about one key question:

Vitalik mentions that many years earlier, there was a push by the community to get stores and online retailers to accept ETH as a form of payment, but as transaction costs on the Ethereum network skyrocketed, this was no longer viable. He says the "ecosystem quietly, mostly gave up on that". 

With scaling and the upcoming Merge, we could be looking at transaction fees on the Ethereum network going right back down. So this might be the perfect time to try and build a solution which allows in-person and online payments to be made in ETH. 

Rollups are a scaling solution. They work by rolling up (hence the name) a batch of transactions, moving some of the computation work that needs to be done off-chain and presenting this rolled-up batch as one single transaction to the Ethereum network. This helps the network process transactions faster. Some rollups also use compression techniques to reduce the amount of data posted on Ethereum. Vitalik believes that working on compression will be really valuable to projects who are currently in the space. 

When there is a lot more data on the Ethereum network, users are going to need software that allows them to access and process all of this data. This will not be something that the Ethereum node will be able to do itself. There are projects trying to tackle this problem currently, but Vitalik thinks more could be done in this space. 

Zero Knowledge proofs are a big deal in the crypto world. In the words of Vitalik:

"It's a way to cryptographically prove that some statement about some piece of data is correct, without revealing the information about why that statement is true. For example, let's say I have an Ethereum address and that address has a valid proof of humanity profile, but I don't have to reveal which proof of humanity profile I have. "

This is quite a technical topic to dive into, so we'll go further into zero-knowledge proofs in a later post. For now, we'll just say that Vitalik thinks there are many zero-knowledge apps that could be built on the Ethereum network, for use cases like privacy-preserving proof of humanity (the example we gave above).

Vitalik says "apart from money and financial applications, things to do with identity are probably the second biggest category of applications on Ethereum". As transactions get cheaper, Vitalik believes more applications could be built in the identity category. Vitalik's dream is to improve the way identity works on the internet. Right now, when you log into a site you sign in with Google, Facebook or Twitter. You have one company which controls your accounts and tracks everything you do, and you don't get much in exchange for this. What if you could sign in to a new site or service with your Ethereum address? 

Before he finishes, Vitalik hammers home why this is all exciting. Two years ago, the Ethereum network was not scalable enough, zero-knowledge proof technology was not as good, so practically you could not build many of the things mentioned in this post.

It's definitely a good time to keep track of what's going on with the Ethereum network because it's likely that more of these new opportunities and areas will open up, as the technology becomes more sophisticated.