The algorithm of litecoin requires a lot of memory instead of processing power and the purpose-built circuits are not considered useful. Several other crypto-currencies have made the same choice. A company called Fibonacci disclaims, however, has developed special machines for litecoin.
Another kind of development is the cryptocurrency ethereum, which poses so-called smart contract. People must sign in in order to spend money from a particular wallet. This may also apply to automation of other issues that are normally regulated by contract.
There is also a ripple - the system is built based on open source solution and the idea is similar to cryptocurrencies. The big difference is that the ripple launched by the company Ripple Labs, formerly the Open Coin.
The usage of ripple is free, however in return Ripple Labs have seized 25 million of the 100 million ripple in the system and 20 million have been given to founders and investors. The skepticism level towards this model is great among proponents of conventional cryptocurrencies.