What happend at the end of credits for X-Men last stand?

There's no post-credit scene in "X-Men: The Last Stand". The film ends with the final battle and the aftermath, with no additional scenes after the credits roll.

This was fairly common for superhero films back in 2006. Post-credit scenes really started to take off in the Marvel Cinematic Universe with "Iron Man" in 2008, setting a trend that most superhero movies follow today.