I’m a big fan of both ExpertFlyer (for looking up fare information and availability) and PointsHound (for booking hotels and earning bonus points). At the Frequent Travelers University two weeks ago, a discount code was handed out that offered 15% off an annual membership to ExpertFlyer’s premium service, normally $99.99 per year. The code has been removed at the request of ExpertFlyer.
There are sometimes other ways to get access to fare and availability information, but ExpertFlyer is by far the easiest to use and the one I recommend when I get questions on this topic. I use it before every trip to check upgrade space, alternate routes, and my VDB probability (compensation for voluntary denied boarding).
Second, I got an email last night that ExpertFlyer is offering its members free Level 2 status with PointsHound and 500 miles after their first hotel booking. This is very similar to the offers from Etihad and Virgin America last week, although I don’t know how long the Level 2 status lasts. Indefinitely? That would be cool. The earlier offer was just for a month, but I couldn’t find any T&Cs for this one.
I recommend you sign up for both services if you’re a frequent traveler. They’ve certainly been valuable to me.