Little Miles Scott had the world watching as he assumed the role of Caped Crusader in San Francisco - as well as the stars who either will or have played Batman in the movies.

Ben Affleck, who is set to play Batman in the Man Of Steel sequel, had nothing but kind words for the five-year-old cancer patient, whose dream to be a real-life superhero was made possible thanks to the Make-A-Wish Foundation.

Michael Keaton seconded that opinion by saying 'it's so cool,' while Christian Bale was equally generous when he stated the whole thing was 'fantastic!'

Miles was diagnosed with leukemia when he was 18 months old; he underwent more surgery last month and the cancer is now in remission.

Miles had a remarkable time on Friday as 'Batkid,' as San Francisco was transformed into Gotham City for the day and the tiny tot got to wander around in his very own 'Batsuit' and battle it out with nemeses The Penguin and The Riddler.

'Batkid. Best Batman ever,' Ben tweeted his response on Saturday.

Batkid prevented The Penguin from kidnapping the San Francisco Giants' baseball team mascot, Lou Seal; stopped The Riddler from robbing a bank vault; and rescued a damsel in distress strapped to a bomb on the city's cable car tracks.
And all of it happened to the cheering of the roughly 10,000 people who lined the streets.

President Barack Obama sent a taped message from the White House saying: ‘Way to go, Miles. Way to save Gotham!’

At the end of the day, Mayor Ed Lee presented Miles with a giant chocolate key to the city while the huge crowd gathered outside City Hall.

Michael Keaton played Batman in the 1989 original film starring Jack Nicholson as The Joker, and its 1992 sequel Batman Returns.

'It's the cutest thing in the world,' Keaton told TMZ while leaving a Beverly Hills eatery. 'It's so cool. Let's not talk about Batman, let's talk about the kid. That's such a cool thing. That's such a cool idea.'

Christian Bale, who's been shooting Exodus in Spain, saw it on the news when he arrived back in Los Angeles ahead of a press junket for his new film Out Of The Furnace.

Bale played the superhero in 2005's Batman Begins, 2008's The Dark Knight and last year's The Dark Knight Rises.

Wasn't that fantastic?' a smiling Bale told Vulture.com. 'I looked on the news and I saw this headline and thought, "What's that?" And I saw all the pictures of him running around and saving people. It's so touching.'

'What's his name, Miles?' the actor went on. 'He must have been bewildered! Hopefully, later on, he'll be able to look back and say, "Oh my God, how amazing."'

On the social networking that made Miles' adventure possible: 'I'm so far behind the times when it comes to things like that, I'm a dinosaur,' Bale admitted.

'I've never been on Twitter, but how great a thing that it can create something like that! I mean, wonderful.
'
This little kid, oh my God — what a wonderful day for the little fella! It's just fantastic, seeing all those people who were out there to support it.'

Miles' super experience happened after his mother Natalie, from Oregon, wrote to the Make-A-Wish Foundation saying her ailing son dreamed of being a mini crime-fighter.

The youngster initially thought he was visiting San Francisco to pick up a Batman costume, and what a wonderful surprise he had when the action started on Friday.