When celebrities pair with a cause, some are quite obvious. Oprah Winfrey publicly supported Barack Obama — a fellow Illinois figure who has often fought similar fights. Politically active actors Tim Robbins and Susan Sarandon have supported those who seek to end battles overseas that they don't approve. Various stars have supported gay rights, civil liberties and other causes that hit close to home.

But some may ask why Daniel Radcliffe would film a public-service announcement in support of a nonprofit that seeks to help gay youths, to which the actor would respond: You don't have to be gay to be a supporter — you just have to be human.

"It's something I've always been quite passionate about," Radcliffe explained to us when he stopped by the MTV studios recently. "Because I grew up around gay men, it was always a natural thing to me. It was never something I ever gave a second thought to."

Founded by the filmmakers of a movie entitled "Trevor," which took home the Oscar in 1994 for best short, the Trevor Project is a nonprofit organization that offers support for lesbian, gay, bisexual, transgender and questioning youths. The group's prevention hotline and trained counselors have helped save many lives of at-risk youth contemplating suicide, as well as fostering safe, inclusive environments at their homes and schools.

"Some are gay, some are straight — didn't make any difference to me," Radcliffe said of his own personal upbringing, which unfortunately isn't always the case. "When I went to my second school, I heard terms like 'puff' and 'homo' getting thrown around. It never occurred to me that some people might have a problem with it."

Now that Radcliffe is an international superstar with an enormous fanbase behind him, he's determined to get the word out that downtrodden LGBTQ youths can depend on the Trevor Project — and those ignorant enough to torment them need to be stopped. "I remember being quite shocked when I was young," Radcliffe remembered of his early encounters with homophobia. "And now I am in a position where I can help an amazing thing like the Trevor Project."

The Trevor help line is a free and confidential service that offers help 24/7. The help line is a no-judgment zone and the trained counselors are always available at (866) 4-U-TREVOR (488-7386).

"The Trevor Project is the only nationwide around-the-clock crisis- and suicide-prevention help line [of its kind]," Radcliffe said of the cause. "[It's designed] for gay, lesbian, bisexual, transgender and questioning youth. There will also soon be a 'Trevor' iPhone application."

For about a decade, volunteers have worked tirelessly to help the Trevor Project — now they have one more very important person in support of their efforts. "There are about 160 people in total who work around the clock, and that number is obviously growing over time. It is an incredible thing," Radcliffe marveled. "I was talking to one of the [volunteers] who said, 'I hate the fact that this needs to exist.' But it's so important that it does."