The state of the art?
It's easy to forget just how bad web sites used to be, even a year or two ago. A visit to Air Canada is a vivid flashback to just how broken a site can be.
Enter the site by pressing "English" and then book your entire itinerary. Whoops. You forgot to press "US Traveler" on the front page, so you're stuck.
The fields are small and hard to navigate. The logic is twisted at best. The hierarchies don't match.
My point is simple: the bar has been raised, folks. If you're not smooth and easy and logical, people will flee.