Kathmandu, Feb. 10 -- Ashrita Furman knows most people think he is crazy and wacky. He has just been in Malaysia, where he slashed over 50 watermelons over the course of a minute, in an attempt to set a Guinness world record. Those melons were placed on his friend Homangi Baptista's head. Baptista shows a video as proof, with Furman wielding a samurai sword and swiftly slicing the melons in two, as another man quickly places another after each slice.

"When you think about it, it does sound silly, but you need concentration to pull it off, and a lot of times, teamwork to get things done," says Furman, in the lobby of Thamel's Hotel Moonlight. The Guinness world record-breaker says he has 800 certificates of recognition, and currently hold...