Mexico charges a departure and airport tax of about US$13 and US$8.50, or the peso equivalent, respectively, when you leave the country. This tax is almost universally included in the price of your ticket, but check to be certain. Traveler's checks and credit cards are not accepted at the airport as payment for this fee.
A 2% tax on accommodations is charged in Los Cabos, with proceeds used for tourism promotion.
Baja California Sur has a Value-Added Tax of 10%, called I.V.A. (impuesto de valor agregado), which is occasionally (and illegally) waived for cash purchases. Other taxes and charges apply for phone calls made from your hotel room.