Rob is in New York promoting his new movie "Remember Me" and the ever-gracious star took time out to talk to his fans.
One love-struck fan toted a huge "Remember Me" poster for Rob to sign and the loveable Brit shouldered it out of the scrum to scrawl on it.
Irish fan Maeve Donovan from County Leitrim said she can't wait to show all her friends her pictures.
"He's so-o-o-o-o cute," she said. "I thought he was going to be one of those fellas who are gorgeous on screen and then so-o in real life, but RPatz is the real thing!"
The 19-year-old said she thought he was going to walk off after just doing a few "but he stayed and did as many pictures and autographs as he could."