there are 210 trillion satoshis available. (American trillions. Note that euros have a different meaning for "trillion")
The currency should be changed so that:
1 bitcoin becomes 1 satoshi
CURRENT VALUE FUTURE VALUE
1 satoshi 1 bitcoin
500 satoshi 500 bitcoins
500k satoshi 500 thousand bitcoins (500k)
500 million satoshi 500 million bitcoins (500mil)
500 billion satoshi 500 billion bitcoins (500bil)
210 trillion satoshi 210 trillion bitcoins (210tril)
Just change the meaning of what we currently call a bitcoin to what is currently called a satoshi.
Bitcoins and satoshis become the same thing and the problem will be solved. The public will understand, and will be excited to get their hands on 10, 100, 1k, 100k, 1mil, 100mil, 500mil bitcoins.
Fractions are poison for the currency.