Credit: Jim Spellman/WireImage

Who says exes can't be friends?

When Demi Moore and Bruce Willis divorced in 1998, the two agreed not only to put their three daughters' needs first, but to remain friends with each other. "It wasn't a piece of cake," Moore, 48, said of their relationship. "It wasn't automatic or easy. It took diligence and effort and even enduring awkwardness, and a lot of general giving on my part and Bruce's part."

Moore married Ashton Kutcher, 33, in 2005, and Willis, 56, wed Emma Heming in 2009. Both Moore and Willis attended one another's nuptials.

But they aren't Hollywood's only friendly exes! Despite splitting in 2007, Cameron Diaz and Justin Timberlake reunited as onscreen lovers in the 2011 film Bad Teacher. Other couples, including David Arquette and Courteney Cox and Kate Hudson and Chris Robinson have stayed amicable after splitting.