Wyclef Jean is one of Haiti's most famous sons, and his tweeting about the earthquake there has been a galvanizing force on the Web.
Jean is most famously a member of the now-defunct Fugees. Publicist Leslie Chasky says he arrived Wednesday in Haiti and is focusing on his family, his Haitian charity and responding to the disaster.
Several of the most popular topics on Twitter referred to a tweet from the singer urging people to send a text to the charity, Yele, to donate $5 toward relief. The number is 501501.
Hundreds are passing his message on by the minute. The Yele Web site is inundated with donations and has crashed under the traffic.
A spokeswoman for the charity says the organization is working to fix the problem and increase the site's bandwidth.