*NSYNC sent us right back to our teens when they reunited on Monday to celebrate their star on the Hollywood Walk of Fame, but things got even more fun when Justin Timberlake made a visit to The Ellen DeGeneres Show . . . and brought his bandmates along for the ride. Justin interrupted Ellen as she was reading him a fan letter, explaining that he'd brought her a gift. Of course, that gift came in the form of JC Chasez, Lance Bass, Joey Fatone, and Chris Kirkpatrick, who sent the crowd wild with their surprise appearance. The guys joked about with their lookalike bobbleheads, looked back at some of their more memorable outfits, and discussed the *NSYNC group chat that allows them all to keep in touch. How much does your inner 15-year-old wish she had access to that?!