By Adam Markovitz
Updated August 19, 2010 at 02:15 PM EDT

Image Credit: Chris Hatcher/PR Photos; David Gabber/PRMark your calendars: On Sept. 10 at 8 p.m. ET, the four major TV networks will all air a star-packed Stand Up to Cancer telethon, featuring appearances by Reese Witherspoon, Stevie Wonder, and Queen Latifah alongside cancer survivors like Lance Armstrong and Christina Applegate. Katie Couric, Diane Sawyer, and Brian Williams will serve as joint hosts of the event. The last Stand Up to Cancer benefit in 2008 raised over $100 million for research.

So plan a viewing party — and in the meantime, check out this clever PSA starring Zac Efron, Vanessa Hudgens, and Dakota Fanning, among others.