Sites I Like

The following is a collection of links that I find particularly helpful when searching for travel deals:

Flight Tools:

ITA software - the best and most powerful flight search engine
Kayak Explore - visualization of flight prices from a given airport

General interest websites/Forums:

Flyertalk.com - Great up to date information on all topics related to travel.  Mostly caters to frequent travelers but great deals on flights and hotels as well as the latest frequent flyer and hotel program information.  See MilesBuzz! for credit card sign ups and bonus point opportunities, Hotel deals and Mileage run deals for bargains on hotels and flights respectively.
Milepoint.com - More of the same

Blogs:

View From the Wing

Million Mile Secrets

Frugal Travel Guy

The Points Guy

Mommy Points

Loyalty Traveler

One Mile at a Time