Personally, I don't book travel on the internet, but I use stuff like Expedia and Travelocity to give me a general sense of what's available.

Here's a little test you can do for yourself, and one which I've done many times....

Look up a flight or travel package on any of these sites and find the best price you can. Then walk into a travel agency and ask what the best price you can get on the same package. Don't bother telling them you've looked it up on the net.

I will all but guarantee you that the travel agent can find you a better deal.

I've done this now over a dozen times, and in every single case, the agency was cheaper.

As I've heard it explained, most of the internet sites pre-book ticket blocks, and cannot acquire more once booked, which means they can't access changes or upgraded deals offered by airlines.

I don't know if that's the real story, or not, but I do know that I'm sticking with booking travel through an agency.