Several more celebrities have signed up to join in the "America: A Tribute to Heroes" telethon tonight, which will be broadcast simultaneously on more than 30 television networks and 8,000 radio stations nationwide.

The unprecedented event, which was organized by the nation's "big four" networks -- ABC, CBS, NBC and Fox -- will air tonight at 9:00 p.m. EST to raise funds and raise the spirits in the wake of the terrorist attacks on America.

Titled "America: A Tribute to Heroes," the live two-hour, commercial-free, simulcast is meant to bring our nation's family together to salute the American spirit. The telethon will raise funds for a long-term relief effort for the thousands of Americans who directly suffered from the terrorist attacks in New York, Washington and Pennsylvania Sept. 11.

From New York and Los Angeles, celebrities from television, feature films, music, sports, and news will take part in the event, billed as an evening of "music, memories, hope and inspiration."

Actors and celebrities who have volunteered to answer phones for the telethon include, in albabetical order: Halle Berry, Cindy Crawford, John Cusack, Benicio Del Toro, Danny DeVito, Sally Field, Andy Garcia, Whoopi Goldberg, Goldie Hawn, Salma Hayek, Michael Keaton, Reba McEntire, Jack Nicholson, Al Pacino, Rhea Perlman, Brad Pitt, Chris Rock, Meg Ryan, Adam Sandler, Sylvester Stallone, Ben Stiller, Mark Wahlberg and James Woods.

Performers just added to the event include Celine Dion, Enrique Iglesias, Limp Bizkit, Sting and U2. Dion will sing "God Bless America" from New York.

Previously scheduled entertainers include, in alphabetical order: Bon Jovi, Amy Brenneman, Mariah Carey, Jim Carrey, George Clooney, Sheryl Crow, Tom Cruise, Cameron Diaz, The Dixie Chicks, Robert De Niro, Clint Eastwood, Calista Flockhart, Dennis Franz, Kelsey Grammer, Tom Hanks, Faith Hill, Billy Joel, Alicia Keys, Conan OBrien, Tom Petty, Ray Romano, Julia Roberts, Paul Simon, Will Smith, Bruce Springsteen, Sela Ward, Robin Williams, Stevie Wonder and Neil Young.

All funds raised from this program will go to the relief effort. All costs will be underwritten by the networks, and everyone involved will be donating his or her time and resources.

The tribute will be broadcast live in the Eastern and Central time zones and tape-delayed in the Mountain and Pacific time zones. It will also be video-streamed on the Internet. All of the other broadcast networks, cable networks and radio networks are being invited to carry the event.