Andreas Antonopoulos, Blockchain.info
Antonopoulos is the Chief Security Officer of Blockchain.info, a popular Bitcoin wallet service that also records every single Bitcoin transaction as it happens. He's also likely the closest thing there is to a Bitcoin missionary, traveling from conference to conference to educate people on what Bitcoin is and how it works.
Many of his presentations are on YouTube. This one in particular is especially accessible.
When there began to be doubts that Newsweek had properly identified "Satoshi Nakamoto" (it suggested that he was actually Dorian Nakamoto of Temple City, Calif.), Antonopoulos started a Bitcoin fundraiser to send money to Nakamoto for his troubles in being hounded by the media. Antonopoulos raised 44.64 Bitcoins worth over $28,000.
Gavin Andresen, Bitcoin Foundation
Andresen is Chief Scientist of the Bitcoin Foundation, a non-profit organization that exists to "standardize, protect and promote the use of Bitcoin cryptographic money for the benefit of users worldwide."
He became project lead for Bitcoin in May 2010 and has communicated directly with "Satoshi Nakamoto" in the past, but only ever via email and Web forums. Andresen has rather high-level access to the Bitcoin network as well, holding an "alert key" that lets him send messages about the status of the Bitcoin network that enables those messages to appear in every single Bitcoin client as users run them.
Barry Silbert, Bitcoin Investment Trust
Consider the following two sentences from Crain's:
At 13, Barry Silbert was making a business out of trading baseball cards. He spent his bar mitzvah money on stocks, and at 17 was the youngest person to pass the Series 7 stockbrokers' exam.
Barry Silbert knows a thing or two about money, so it's only natural that the CEO and founder of SecondMarket, a place for buying and selling illiquid assets, would also be interested in Bitcoin. Silbert founded the Bitcoin Investment Trust, a "private, open-ended trust that is invested exclusively in Bitcoin & derives its value solely from the price of Bitcoin." His business exists to help Bitcoin speculators buy, store, and protect large numbers of Bitcoins.
Fred Ehrsam, Coinbase
Ehrsam is co-founder of Coinbase, the go-to Bitcoin exchange for many, many people. But Coinbase also serves merchants as a means of processing Bitcoin transactions and converting the Bitcoin income into more conventional currency.
Already Coinbase handles Bitcoin payments for major companies like Overstock, OKCupid, and Reddit.
Jeremy Allaire, Circle
Allaire is already an established entrepreneur, having started the Allaire Corporation with his brother in 1995 to create ColdFusion, a web development language. They sold to Macromedia in 2001 and Allaire became Macromedia's CTO. While Allaire's had some other ventures in the meantime, his latest is Circle.
Circle provides consumers a means to store, send, and receive digital currency. For larger businesses and organizations, Circle offers tools to make it a snap to accept Bitcoin for donations and purchases.
He's a true believer, saying in an interview with Coindesk that "Bitcoin and digital currency represent a once-in-a-lifetime opportunity to shape the future of the Internet and global commerce."
Jeremy Liew
Liew works for Lightspeed Venture Partners and was the first investor in Snapchat. He's a staunch advocate for the currency, already having invested in a couple Bitcoin-related startups.
He wrote an excellent, plain-language take on Bitcoin for TechCrunch:
Mainstream adoption will require bright line regulatory compliance by all elements of the Bitcoin ecosystem. That is why last month’s guidance on virtual currencies from FinCEN (part of the U.S. Treasury) caused Bitcoin prices to go up. As Bitcoin gets closer to the U.S. regulatory umbrella, it moves closer to legitimacy. These rules and the ones that will follow will increase the overhead costs of all players in the space, but that is a small price to pay for legitimacy.
The Winklevoss twins, Winklevoss Bitcoin Trust
The Winklevoss twins are likely most famous for their early entanglements with Facebook, but they've lately established themselves as heavyweights in the Bitcoin world.
Most recently, they booked a trip to space with Virgin Galactic and paid in Bitcoin, but they also plan to establish a new Bitcoin index called the "Winkdex."
Brett Stapper, Falcon Global Capital
Stapper ran several companies before throwing his hat into the Bitcoin ring by co-founding Falcon Global Capital. The company functions like a Bitcoin investment fund and insures customers' deposits.
Stapper and the Falcon Global Capital team are currently making efforts to buy the 27,000 Bitcoins seized by the FBI in the Silk Road shutdown.
Stefan Thomas, WeUseCoins
WeUseCoins is one of the most user-friendly onramps to becoming a seasoned Bitcoin user. The site offers a number of unintimidating guides and walkthroughs designed to make Bitcoin as easy to understand as possible.
Stefan Thomas is the man behind the site, advocating for Bitcoin's mainstreaming. He's another one to look for speaking at conferences on how and why Bitcoin matters.
Chris Dixon and Marc Andreessen, Andreessen Horowitz
VC firm Andreessen Horowitz is into Bitcoin.
Marc Andreessen, father of the modern Web browser and noted investor, has taken up the Bitcoin mantle in a big way, investing in Bitcoin companies and even taking to the New York Times op-ed section to explain why Bitcoin matters.
Chris Dixon is another brand-name investor at Andreessen Horowitz and cryptocurrency advocate. While it's not quite the New York Times, he explains on his personal blog why he's interested in Bitcoin:
Bitcoin is a serious proposal for dramatically improving the payments industry. There are plenty of open questions but I think it’s an experiment worth running.