SE has set up a program of partnering with other friendly sites, we help each other primarily through cross promotion; though occasionally there are other things we do for each other.
One example is our partnership with the team creating the Enterprise: Temporal cold war mod for Half-Life 2. As well as cross-promotion they have agreed to provide TU with exclusive material such as screen-shots.
Many of our partners have been gained via the SE ambassadors program. This works by SE sending ambassadors to other forums where they promote the campaign, answer questions, provide news, and serve as liaison between the two sites. Please visit our thread for information.
Active Campaign 
