I use travelocity a lot. I like the feature on their website (perhaps others have it?) that allows you to use a flexible dates search. I just leave it wide open and then see when the best deals are. I often fine that leaving one day earlier and coming back two days later (or something like that) can save me quite a bit. As for hotels, I sometimes find better deals - sometimes not. Always shop around, though...you would be suprised at the differenes sometimes.
Also, I have at times found wild deals on travelocity. I don't know if they still do this, but they used to bundle a air+car or air+hotel together at insanely low prices. For example, if my wife and I were traveling -= we could get plane tickets at $300 each, so $600 dollars total. But, if we were willing to rent a car as well, or take a hotel - we could get the total trip (including the car or hotel) for $500. We actually took a trip to Minnesota where we had to stay in a particular hotel, but we just took the cheaper flight+hotel option and just never showed up at the hotel that went along with it. I have no idea how this happens - but it has worked just fine for us the few times when we found it. If this sort of deal is available, it will show up as a tab at the top of the search results page. Most of the time you will see these and they will be more expensive than the flight, but still cheaper than if purchased separately.