http://www.tripadvisor.com/Travel-g147270-c595 48/Cuba:Caribbean:Tipping.Gifts.And.Money.html
Says:
The Exit Tax is $25 CUC per person (even children) so remember to save this and budget for it.
Any info indicating taking USD to Cuba must be from before November of 2004.
Since then Castro decided that the currency of choice used in the tourist industry would be the Cuban Convertible Peso (CUC). They had already started this conversion in October (04).
The Cuban Convertible Peso (CUC) was revalued in April of 2005 at 8% higher than the USD (use this for exchange purposes only) So ... with an extra 10% "penalty" for exchanging USD in Cuba plus the 8% for revaluation, you would be losing 18% on exchange which has effectively restricted the use of the USD in Cuba.
Euros and pounds, CDN are fine, bring cash and exchange at the airport in Cuba, at your hotel (small comission) or at a bank/money exchange (bring your passport if drawing money from a credit card). Count your money at the counter and get a receipt. You can not purchase CUC outside of Cuba.
Travellers Cheques are fine (no USA afiliation) but ... you still have to line up to get money at the bank or exchange counter. If lost or stolen ... they will not be replaced until you return home from your trip. ATM's ... very few and infrequently filled ... debit cards do not work (except from UK with Visa logo on it) and the ATM's only accept Visa CCs The following diagram shows how to fill out the Cuban Tourist Visa Card Two sides Entery/Exit You can left click and save so it can be enlarged if needed.