1. Easy to carry/transfer/store
2. Almost never perish
3. Universal equivalent (wide acceptance)
4. Tax free
Currency itself does not have any utility, but in fact the utility is the biggest of all goods/services because of its universal equivalent property. It actually has all the utilities
In order to have that universal equivalent property, it must be widely accepted by all the merchants/producers. For fiat money, this is done by law enforcement, but for other natural currencies, that wide acceptance would take a long time to develop
Here, let me save you a lot of time and trouble: http://wiki.mises.org/wiki/Money
Good, these definitions especially the commodity money is easy to understand, different than the money wiki at wikipedia, where they use many different confusing abbreviations and terms (typically seen in a scam)
I still like to do the research by myself so that I can make more progress than books. Tax free for example is my discovery