Madonna gave film students at New York's Hunter College a huge surprise yesterday (18OCT05), when she walked in unannounced during one of their classes.

The students had just seen an advance screening of Madonna's tour documentary I'M GOING TO TELL YOU A SECRET, when the pop superstar walked through the doors.

Her appearance was filmed for the MTV series STAND IN, where celebrities such as Marilyn Manson, Melissa Etheridge and Kanye West have appeared as guest lecturers at colleges.

The 47-year-old MATERIAL GIRL, who was raised a Roman Catholic, took questions from the students and explained why she has become fascinated by Jewish mysticism.

She said, "Being a celebrity, you can get very caught up and seduced into believing and thinking that what you do is the most important thing in the world and get very attached to material things. I'm guilty of that and I'm still guilty of that, but hopefully I'm becoming less attached.

"Kabbalah may not be the best thing for everybody. It has worked for me."

Madonna, married to film-maker Guy Ritchie also offered a piece of personal advice: "The best thing to do is find one person in your life and try to love them unconditionally. If you've accomplished that, you've accomplished a lot."