Just before 5 p.m. on Wednesday, January 13, a magnitude-7 earthquake struck Port-au-Prince, Haiti, flattening hundreds of buildings and killing as many as 100,000 people. (Related slideshow: Haiti Earthquake: A Bird's Eye View of the Disaster .) Within minutes, the news had spread to Facebook and Twitter. Within hours, Google Earth and had uploaded post-quake satellite images, giving anyone with computer access a firsthand look at the breathtaking wreckage. Bing's Virtual Earth plans to follow suit.
"In terms of information and awareness, this is the most immediate disaster we've ever had," says Marguerite Madden, a geography professor at University of Georgia who cochairs the Gi4DM summit, where attendees discuss how to leverage spatial images during times of crisis. "Within 24 hours, it was literally everywhere."
As relief workers struggle to help Haitians in need and loved ones panic from abroad, several Web sites--including the aforementioned power players--have released apps and images that are "absolutely crucial" to crisis management in Haiti, says Madden. And text message-based systems have become an integral part of donations. Here's an in-depth look at how they work, and who they help.
The world's most familiar mapping tool is both raising awareness and helping relief workers find the neediest disaster areas. Its post-quake images came from GeoEye and DigitalGlobe satellites, and were uploaded at approximately 7 p.m. last night. Currently, a team is working to get a portable version of Google Earth to workers on the ground in Haiti. According their Twitter feed , "All being well, [it] will arrive tomorrow."
Google Map Maker
This submit-your-own map feature--mainly used to gather data about lesser-developed countries--was integral during the aftermath of Hurricane Gustav , which hit Haiti in 2008. Since then, says Google, "many committed individuals have contributed rich data for the country, and now maps of Haiti  appear on Google Earth and Google Maps." Developers have already given their data to U.N. earthquake relief workers, and are encouraging Web users to share any local knowledge that will help them build a better map of Haiti .
Using this site  (powered by data from the USGS ), those with friends and relatives in Haiti can input an address in English or French to gauge how hard a particular home was hit. It's been live for 14 hours, and received more than 11,000 hits.
Facebook and Twitter
Per usual, users have leveraged the social networks to share news and post images . But they've also helped fundraising campiagns go viral by posting status updates such as, "SPREAD THE WORD! HELP HAITI BY TEXTING 'YELE' TO 501501 AND DONATING $5 TO THE WYCLEFF JEAN FOUNDATION."
Text to Donate Programs
Speaking of Yéle , a handful of Haiti aid campaigns have gone viral , making aid easy for text-happy mobile phone users. Simply text a word to number and a small donation is tacked onto their wireless bill.
Yéle's Haiti aid text campaign, which started Tuesday and is an extension of the charity run by Grammy-winning musician and Haitian native Wyclef Jean, has already raised more than $800,000 in donations by 3 p.m. Wednesday, largely $5 donations made by texting YELE to 501501. Some have, however, questioned  whether giving to a grassroots organization in the event of a disaster like this is the best move, no matter how easy or well-intentioned. A small organization without an on-the-ground infrastructure can find itself saddled with administrative costs. Yéle, for example, spent more than a quarter of money collected on administrative costs in 2007.
By comparison, the William J. Clinton Foundation  has pledged 95.9% of its proceeds go to programs. Those who text "HAITI" to "20222" can automatically donate $10 to the Clinton Foundation's Haiti Relief Fund (it's charged to your cell phone bill). The foundation has thus far concentrated on ongoing efforts such as HIV-AIDS, sustainable economies, the Clinton HIV/AIDS Initiative (CHAI) to turn the tide of the HIV/AIDS pandemic in the developing world. It's also focused on access to affordable drugs and diagnostics to more than 70 countries, and staff work on the ground in more than 20 countries, which explains its ability to hold down admin costs.
Of course, anyone watching coverage of the crisis has spotted the iconic Red Cross emblem on backs and chests of aid workers starting to trickle into Port-au-Prince. American Red Cross  has pledged $1 million toward relief and has its own program offering those who text "Haiti" to 90999 to make $10 donations.
Lydia Dishman contributed to this report.