Various schemes to achieve entirely electronic currency, usually designed to be secure and untraceable using some sort of cryptographic technology, have been implemented. Some have gone defunct; Bitcoin is the major one currently still in use.
- Libra 
- Permacoin (also a filesystem)
- Storj (another currency/filesystem scheme)
Not distinct currencies, but ways to move existing types of currency quickly.
- Proposal for a 'distributed' currency (as a Bitcoin replacement)
- British Drivers Can Pay for Parking with Chestnuts
- JP Morgan pursues Bitcoin-like patent
- How scientists taught monkeys the concept of money. Not long after, the first prostitute monkey appeared
- Native Americans adopt bitcoin clone as official currency
- Why Auroracoin will be huge
- Rep. Polis Asks Treasury To Ban Dollar Bills, Mocking Senator's Request To Ban Bitcoins
- On April Fools' Day, Stack Overflow introduced Unicoins.
- Discussion of Ethereum, yet another cybercurrency