Oddly enough, there are no alternatives to MONEY 2.0. This may come as a surprise, as there are actually just a couple of basic principles that need to be adhered to in order to create a serious money contender. To improve the current situation, any medium of exchange will work that is independent of the traditional currency system, free of ideological burdens and optimized for the mutual exchange of goods and services, without privileging or disadvantaging (let alone excluding) any group of participants.
Unfortunately, to this very day, a currency that meets these simple criteria hasn't been implemented. Although alternative payment systems have kept emerging for the past several decades, their constructional deficits are too serious to tap the true potential that lies in alternative currencies. The bulk of these creations belong to one or several of the following categories:
Complementary currencies defining themselves via traditional money
To bring these complementary currencies into circulation, market participants first of all have to own traditional money, which they can then use to buy the new currency. As a consequence, the new currency is not only unfit to ever replace traditional money (after all, it relies on its existence), but also, all downsides of traditional money are imported into the new system.
Typically, complementary currencies are issued as regional money, which is how they do, in fact, unfold certain benefits: Since the local currency is typically not accepted outside of the region, it serves as a stimulus for the local economy and advances regional customer awareness. The actual problems of the current financial system, however, stay unaffected.
Local exchange systems
Local exchanges grant the right to issue money to their members, but typically fail - directly or indirectly - because they are unable to enforce their rules. Without enforceability, important principles degenerate to noncommittal guidelines and can only be relied on, as long as participants know each other and can add personal authority where needed. However, since the usefulness of any exchange system rises exponentially with the number of participants, the two most important parameters - safety and usefulness - are de facto established as antagonists.
Another problem with local exchange systems is the fact that they particularly attract members who either want to use an alternative medium of exchange (e.g. by conviction), or who even have to, because, due to personal circumstances, their access to the traditional medium of exchange ("money") is limited. As a result, these exchanges are typically tailored to those two user groups and feature the respective bias (e.g. by equating the value of qualified work with that of unqualified work). While it seems like a great idea to assist those who are at an economical disadvantage in the current system, utilizing an alternative currency for this purpose means that the original goal, creating a neutral medium of exchange, is lost sight of.
This is all the more problematic, as the average money user definitely has a choice and is unlikely to even go near a currency that doesn't live up to is most basic functions, let alone puts him at an even greater disadvantage than the traditional medium of exchange already does. (It is therefore hardly surprising that the variety of goods and services available in local exchange systems doesn't come close to what can be bought for traditional currency - which, in turn, doesn't exactly tempt other potential participants to join.)
Credit clearing and barter clubs
In clearing systems, which are typically designed for companies and businesses, participants are required to bring in tangible securities, similar to those known from traditional banking, upon which the system administrator approves an equivalent line of credit in alternative currency.
Of all existing alternative currency models, credit clearing systems are definitely the most advanced: The ability to issue money is given to those doing business, and an adequate level of security is usually achieved through a sophisticated body of rules. The big downside, however, lies in the fact that these clubs aren't open to individuals (and, due to their bureaucratic complexity and the need for a minimum business volume, can hardly ever be).
Details
• Some people claim that complementary currencies can be decoupled from the traditional currency system. That assumption, however, hardly stands up to practical judgment: Complementary currencies derive their stability from their backing by traditional money (a central authority guarantees that the "new" money can be changed back to "old" money at any time). Decoupling would therefore resurrect all problems that were disregarded by coupling with the traditional currency in the first place. Questions of money creation (how do I bring the new currency into circulation once people can't buy it with old currency any longer?) as well as of value (what can I use as backing instead of the old currency?) would no doubt only be the tip of the iceberg. In essence, it would be necessary to reconstruct the new currency from scratch (which is, likely, why this "possibility" has never been implemented in practice).
• Whether it's the rules of local exchange systems attracting certain members, or the composition of these systems leading to certain regulations, is a chicken and egg issue - albeit one that is quite irrelevant for the consequences of this problem. On the other hand, the question to what extent people, whose personal circumstances force them to use alternative currencies, would still prefer to use traditional money, if they only had the choice, seems far more consequential.
• Upon closer look, using "hours" as a measure of value in alternative currency systems appears to be nothing but eye wash. The claim that all hours have identical value is simply untenable, and once that is clear, different payment for an actual hour of work (depending on type and quality) becomes almost inevitable - unless, of course, the participation of qualified specialists (like car mechanics or doctors) isn't regarded as important. If, however, an hour of work can be paid for with any quantity of currency units, the reference value of an "hour" is inevitably lost. Two ounces of gold may hold the same value - two hours (provided by different people with different skills), however, definitely don't.
• Some people claim that complementary currencies can be decoupled from the traditional currency system. That assumption, however, hardly stands up to practical judgment: Complementary currencies derive their stability from their backing by traditional money (a central authority guarantees that the "new" money can be changed back to "old" money at any time). Decoupling would therefore resurrect all problems that were disregarded by coupling with the traditional currency in the first place. Questions of money creation (how do I bring the new currency into circulation once people can't buy it with old currency any longer?) as well as of value (what can I use as backing instead of the old currency?) would no doubt only be the tip of the iceberg. In essence, it would be necessary to reconstruct the new currency from scratch (which is, likely, why this "possibility" has never been implemented in practice).
• Whether it's the rules of local exchange systems attracting certain members, or the composition of these systems leading to certain regulations, is a chicken and egg issue - albeit one that is quite irrelevant for the consequences of this problem. On the other hand, the question to what extent people, whose personal circumstances force them to use alternative currencies, would still prefer to use traditional money, if they only had the choice, seems far more consequential.
• Upon closer look, using "hours" as a measure of value in alternative currency systems appears to be nothing but eye wash. The claim that all hours have identical value is simply untenable, and once that is clear, different payment for an actual hour of work (depending on type and quality) becomes almost inevitable - unless, of course, the participation of qualified specialists (like car mechanics or doctors) isn't regarded as important. If, however, an hour of work can be paid for with any quantity of currency units, the reference value of an "hour" is inevitably lost. Two ounces of gold may hold the same value - two hours (provided by different people with different skills), however, definitely don't.