I agree with robyng about not needing to get the lowest price on everything. When I travel to Asia, I always give tips to everyone even though it might be included. It just makes me feel good to help someone else out, who doesn't make that much.

If a taxi in Thailand or Vietnam charges me too much, who cares? What will I loose $1-5. That is just tip money for a taxi in the U.S.

Spread the wealth people and feel good about it. Maybe that taxi driver or tour guide will be able to buy his or her kids an extra toy or ice cream because of you. Doesn't that make you feel good?