Website for booking multi-flight trips
 

I've used sites like Travelocity before for simple trips (e.g. round-trip airfare+hotel to one city). But it seems none of the main sites allow for multi-city traveling. E.g. they only have one-way flights or round-trip fares. I'm looking to book a trip that has me going from Vancouver to Toronto for a few days, then from Toronto to NY for a week, then from NY back to Vancouver. Any travel booking sites that allow multi-city booking together?

edit: I got www.kayak.com . any other suggestions?

There's a link on those travel sites, as well as airline sites that allow you to select multiple destinations.

Judging by your flight plan though, I think it will probably be the same if you booked each flight as a one way flight as you're only flying within North America.