Those citizens of the following countries or regions must obtain a visa to travel to Mexico. For recreation, business or any unpaid activity in Mexico that does not exceed 180 days, must apply in any Mexican consulate visitor visa without permission to engage in gainful activity.

A foreign who has any of the following documents shall not require Mexican visa:

a) A document certifying permanent residence in Canada, USA, Japan, the United Kingdom of Great Britain and Northern Ireland, or any of the countries of the Schengen Area;

  b) Valid visa from the United States of America;

  c) Card APEC Business Traveler (ABTC) approved by Mexico;

  d) Certificates testifying as a crew member of the aircraft that arrives, or

  e) Book sea, if a member of the crew of the vessel up to the Mexican port in international voyage. If the above by air crew to enroll in a national ship anchored in port, you must present the book sea, document certifying their enrollment, data from the boat and the Mexican port where this is located.
http://www.inm.gob.mx/index.php/page/Paises_Visa/en.html

Nationals of the following 65 countries and jurisdictions do not require a visa to enter Mexico as tourists, visitors in transit or business visitors. Tourists and business visitors can stay in Mexico for up to 180 days. Visitors in transit can stay for up to 30 days. However, foreigners that do require a visa for Mexico may visit Mexico if they hold a valid United States visas or are permanent residents of the United States, Canada, Japan, the United Kingdom and countries that comprise the Schengen area.[
http://en.wikipedia.org/wiki/Visa_policy_of_Mexico