How widely available is hydrogen?

Hydrogen is the most common element in the universe it makes up 75% of all baryonic mass in the universe. However it is very light gas in an Earth;y environment, and all the free hydrogen on Earth has floated to the top of the atmosphere and been blown away by the solar wind. This means there is not a lot of hydrogen in Earth. However Earth's water contains Hydrogen and as such, although it is bound up in a compound, there is an abundance of Hydrogen available to man (with a bit of work to extract it form the water).