I'm 0-2 so far with travel agents here in Singapore. We used one agent for our Depavali trip and he messed up costing us a bunch. I used a different agent to book my trip back to the USA for Christmas. I booked back in August. Due to some lack of communication between Northwest Airlines and my agent, my ticket has now doubled in price. I am not amused.
And so, I spent a chunk of time online tonight to see if I could find replacement airfare. In the process I learned three things...
1. Many of the discount airfare sites such as Travelocity and Orbitz can only book flights originating in the USA.
2. As bad as the new price for my ticket is, my travel agent was quoting me the cheapest current price.
3. Kayak.com finds the most flights at the best prices.
Kayak is an interesting site. It really is a meta search engine. It checked over 300 airlines. It found far more flights from far more carriers than the other flight search engines I tried, and I tried a bunch of them. It found prices as cheap as the carriers' web sites which usually boast that they have the cheapest flights. Kayak's price quotes include all airport taxes.
I hope you never find yourself in my position. But if you do, check, Kayak. They also book hotels and rental cars.