Passport stamp is not put by Cuban Customs on your passport, so if you want Cuban stamp on your it, you have to expressly request to custom officer before leaving the country.

In case you booked a Casa Particular
on CaseCuba.com, you can use the
adress provided by us on the Tarjeta
Turistica, being all our houses
authorised by the Cuban Tourism
Ministry. If you haven't booked
a casa yet, click
here.
When leaving Cuba, remember that all international flights are subject to 25 CUC airport tax to be payed locally cash in CUC; so remember to save 25 CUC for this purpouse.
Be aware that entry regulations may be different, depending on your nationality, so before leaving check the entry
details at the Cuban Embassy in
your country. Check also these links if you want to get informations about Business Visa: