Zimbabwe switched to the US Dollar in April 2009, so these notes are no longer in use.
The picture may be funny, but it was not funny to the poor and middle class of Zimbabwe that quickly saw the value of their earnings disappear and, yet, had no access to foreign currency.
To this day, even with the use of the USD, Zimbabwe struggles with a shortage of small notes. ATMs only give out USD 50 and USD 100. With 68% of the population living on less than $1 a day, do you think they can afford to take out USD 50 at a time? Further, since Zimbabwe doesn't receive direct currency shipments from the US Federal Reserve, there are no coins in circulation and $1, $5, and $10 bills are hard to come by. Thus everything costs a multiple of $1 or $5. If you want to buy a soda that should cost 0.50 cents, you will need to buy two at a time. If you are a shop owner and a customer gave you a $20 bill for a order costing $18, you are likely to give $5 of change because you have no $1 bills.
For those living on less than $1 a day this means that their livelihood depends on bartering rather than currency.
And I haven't even begun to mention the ruined economy that has turned from one of Africa's strongest to one that can't even feed its population. An estimated 95% of the Zim population is unemployed.