[abb]

http://projects.exeter.ac.uk/RDavies/arian/origins.html

Functions of Money
Specific functions (mostly micro-economic)

Unit of account (abstract)
Common measure of value (abstract)
Medium of exchange (concrete)
Means of payment (concrete)
Standard for deferred payments (abstract)
Store of value (concrete)

General functions (mostly macro-economic and abstract)

Liquid asset
Framework of the market allocative system (prices)
A causative factor in the economy
Controller of the economy

[expat_panama]

those are the classic criteria; for me the only way to think of ‘gold as money’ is by completely throwing logic out the window.

[palmer]

Specific functions (mostly micro-economic)
Unit of account (abstract)
Common measure of value (abstract)
Medium of exchange (concrete)
Means of payment (concrete)
Standard for deferred payments (abstract)
Store of value (concrete)

General functions (mostly macro-economic and abstract)
Liquid asset
Framework of the market allocative system (prices)
A causative factor in the economy
Controller of the economy

Bitcoin performs the specific functions, even the store of value will be plausible as it matures. The general functions will come with time also and ironically some by tying one's Bitcoin to a precious metal or other commodity. There are companies in that space already. Even if Bitcoin fails, some technology like it will endure.