Viator - tours, activities and things to do: 
Viator is the leading online provider of destination travel products: sightseeing tours, theater tickets, attraction passes, theme parks, even zero gravity flights...the things you do when you get there. Our market-leading selection of products includes 4,000+ tours and attractions, in over 400 destinations located in 65+ countries worldwide. A sampling of our product offering: Whale Watching, Helicopter Tours, Classes, City and Rail Tours, Cycling & Hiking Tours, Airport Transfers, Dinner
http://www.virtual-travel.info/viator.html

Puerto Vallarta vacations 
Compare and save on Puerto Vallarta vacations, all inclusive packages and Puerto Vallarta travel services. Our agency has a AAA rating from the Better Business Bureau and our travel advisors are Puerto Vallarta certified experts.
http://www.itmco.com/puerto_vallarta_vacations_all_inclusive_packages.asp

Expedia Travel 
Expedia Travel are an online tour operator selling hotel reservations, flight tickets, cruises, car hire and vacation packages throughout the world. Holidays are sold by destination and also by theme including adventure, family and romance vacations. All products can be bought online by credit card.
http://www.expedia.com/

Destinology 
Providing tailor-made luxury vacations to destinations worldwide, including the Caribbean, Dubai and the Middle East, South Africa and more. From city breaks to unique honeymoon retreats, Destinology have a wide range of luxury vacations.
http://www.destinology.com