A very comprehensive flight search website ...

[Smiles]

. . . which I had not come across before: http://www.kayak.com/

Results of a search produce huge numbers of choices, all listed as to your own criteria in a pretty sophisticated and easy-to-navigate viewing page. Very quick loading as well. All results are in US dollars.

I have a couple of favourite search sites I have used many times, but this one's new to me ... perhaps to you as well. If any particular flight I take is of the more complicated type (as this next November flight will be) with multiple stops for various lengths of time I would normally use a travel agent. But for the usual Vancouver>>Bangkok>>Vancouver simple stuff, these web based flight searchers are at least as good ~ if not slightly better. At least as far as ticket cost is concerned.

Cheers ...

[Hmmm]

It's great that a lot of these tools that were once only available within the industry are now available to all.

My current favourite for finding flights / prices is this one:
http://matrix.itasoftware.com/cvg/dispatch/prego
(guest login available).

I also like this one for tracking real-time status and arrivals / departures at any airport for any or all flights ...
http://www.flightstats.com/go/FlightSta ... ByRoute.do (http://www.flightstats.com/go/FlightStatus/flightStatusByRoute.do)

When deciding when to book, it can be important to know how many seats are left in a particular class, which you can find here...
http://www.flyaow.com/classamex.htm
... although you then have to figure out how to read output like this J9 C9 Z3 D3 S9 B9 M9 K9 H9 L9 Q4 T4 V4 W4.

kayak.com looks nice, but not sure about the results. Prices seem high, and it doesnt seem to know about the budget airlines.
Searched for BKK to Saigon, it found flights starting at $534USD. You can get this ticket around $180USD elsewhere.
Searching for BKK to Phuket, it only finds Thai and Bangkok Air, with prices starting at $217USD. There are a lot more airlines flying this route, a lot cheaper.
Also tried to find a flight from BKK to Luang Prabang, it was unable to find anything, direct or indirect.

[Hmmm]

These tools access flight databases maintained by a small number of companies for all major airlines, and also handle flight booking data. I believe that few if any of the budget airlines subscribe to these services. It is presumably cheaper for them to run their own booking systems.

A further complication now is that you may have to enter DMK rather than BKK into these search engines, as that's where some of the airlines fly from.

Price availability varies day by day. Prices for the same flight on the same day usually vary by only by a small amount. Having found a flight, sometimes it is cheaper to go to the airline's website, sometimes not.

Plenty of BKK or DMK to LPQ on my itasoftware link above.

I had been using internet to book flights when I was living in Sydney, and was always happy with it. But here in Bangkok there is a greater range of airlines to choose from, and the cheap flights here seem to be with the small travel agencies dotted around the place and in ads in the newspapers such as Bangkok Post.