"Grey's Anatomy" vets Katherine Heigl and T.R. Knight have moved on from the ABC drama, but they're still tight. In 2009, he publicly applauded her decision to adopt a baby girl, saying, "I'm so happy for her and [husband Josh Kelley]." John Shearer/WireImage.com - July 16, 2009
From Zac and Ashley, to George and Julia, check out the pics of famous boy-girl BFFs.