TabSites allows you to easily create and manage custom tabs and run promotions on your Facebook fan page.  They offer both a drag and build system  or the ability to use a simple engagement app setup process to run promotions and contests on a tab.  Powerful features include ability to run Sweepstakes, import your blog, add YouTube Videos, add product slideshows, and more!  There is a FREE Basic version as well as three paid plans with added features. The nice thing is they offer a 14 Day Free Trial to take if for a test drive.