Get your VCRs ready, this is really one of those rare, genuine hooray-for-Hollywood moments.

A who's who of entertainers--from Tom Cruise to Tom Hanks to Tom Petty--has agreed to assemble Friday night for an unprecedented telethon on ABC, CBS, NBC and Fox to aid the victims of last week's horrific terrorist attacks.

The live two-hour event, called America: A Tribute to Heroes, will "raise funds and raise the spirits of all who have been touched by the horrific tragedy that has struck America," according to a joint press release Tuesday from the four networks.

"America: A Tribute to Heroes will seek to unite a shaken world with words and music while paying tribute to the indomitable spirit, unfaltering fortitude and courage that truly makes America 'the land of the free and the home of the brave,' " the press release reads.

Billed as "an unforgettable and uplifting evening filled with music, memories, hope and inspiration," the event will be simulcast live and commercial-free on ABC, CBS, NBC and Fox from 9-11 p.m. ET and 8-10 p.m. CT (it will be tape-delayed in Mountain and Pacific time zones). In addition, the feed is being made available to all other broadcast and cable networks and radio stations, with the WB, UPN, E!, MTV and VH1 among those planning to carry the telethon. (E! is also planning a one-hour behind-the-scenes preshow airing at 8 p.m. ET/PT.) A Webcast is also expected.

We're not quite sure how it's going to work (we're betting there will be at least one chorus of "God Bless America"), but the sheer star power is staggering.

Participants will include the aforementioned Mssrs. Cruise, Hanks and Petty, along with (in alphabetical order) Bon Jovi, Amy Brenneman, Jim Carrey, George Clooney, Sheryl Crow, Cameron Diaz, the Dixie Chicks, Robert De Niro, Clint Eastwood, Calista Flockhart, Dennis Franz, Kelsey Grammer, Faith Hill, Billy Joel, Alicia Keys, Conan O'Brien, Ray Romano, Julia Roberts, Paul Simon, Will Smith, Bruce Springsteen, Sela Ward, Robin Williams, Stevie Wonder and Neil Young, with more likely to be added in coming days. All are performing for free.

All funds raised by America: A Tribute to Heroes will be earmarked for the postattack relief effort.

The networks say they're footing the bill for the broadcast, which is coming at a time of year when they're usually trying to out-hype and out-rate each other to launch new shows.

With America joining together to mourn the victims and aid in the recovery, the network-wide telethon makes perfect sense. Since last Tuesday's attacks in New York and Washington, D.C., the major networks have pushed back their fall schedules and aired near continuous news coverage of the attacks and subsequent rescue efforts through the weekend.