Charlie, my King Charles Spaniel, has travelled on many trips with me recently.  She has been able to travel in the passenger cabin of the aircraft underneath my seat. If you dog is under a certain weight and the flights is less than 6 hours, most airlines will allow you to take your pet in the passenger cabin - except for the UK.

However, before you pack your bags and head out the door, be aware of the many rules the airlines have regarding pet travel. One rule, which I find annoying, is that they do not allow you to take your little doggie out from the carrier. I had Charlie on my lap and the flight attendants made me put her back in the carrier. They are pretty strict about it.  Also, each airline has different specs for the carrier. They all must have a waterproof bottoms. Be sure to check out this site to make sure you have the right size carrier for your airline: http://www.pettravel.com/airline_rules.cfm

Some airlines charge you $$ to travel with your pet. The link above will give you all the updated info. It is always good to travel with your dog's papers as well (just in case anyone hassels you)! Note: Southwest airlines does not allow pets in the cabin or the cargo