In 2014 I earned 0.000064 worth of Bitcoin through two hours' labour completing a series of tasks via a Web interface. At the time, the equivalent value measured just GBP0.01, or 30-centavos in Honduran Lempira. Some resource was available to laser-engrave the Bitcoin wallet ID and its equivalent value on a penny - this has long since been spent and no doubt dropped out of circulation somewhere.
[user@remotehost ~]$$$ chmod +x BTC0x000hn0017p
chmod: changing permissions of 'BTC0x000hn0017p': Operation not permitted
[user@remotehost ~]$$$ sudo chmod +x BTC0x000hn0017p
[user@remotehost ~]$$$ sudo mv BTC0x000hn0017p BitPenny
In 2018 the amount of electricity consumed by Bitcoin mining in Iceland overtook the country's total household electricity usage.