Stiller tweeted late Tuesday that "people in Haiti need our help and attention right now." Similar tweets are showing up from the likes of Lohan, Hilton, Adam Lambert and Ryan Leslie.
Coldplay singer Chris Martin urges people to donate to a Haiti appeal set up by the charity Oxfam.
Martin says that when he visited Haiti with the charity a few years ago he found a country "of extreme poverty and brutal living conditions."
He notes that many people in the capital, Port-au-Prince, live in shacks. He says the earthquake probably turned the city "into an unimaginable hell."
