Donors clicking to give dollars to relief efforts.

Americans are turning to their computers in overwhelming numbers to aid victims of Hurricane Katrina. Hundreds of millions of dollars are reported zipping across the Internet. While charities know how much is coming in, the big processing firms said that it's often impossible for them to know what's for the disaster and what was a regular gift.

For example, the Salvation Army, in Alexandria, Va., estimated a revenue in online giving of $22.7 million in seven days. That's compared to the just $3 million in the week following the tsunami in the Indian Ocean this past December.

According to Melissa Temme, public relations specialist for the Salvation Army, the day after Katrina surged through the Gulf Coast, "(online) traffic was so great, our servers couldn't handle it. I guarantee we've never seen this level of traffic before."

Similarly, of the $409 million the American Red Cross (ARC) has received in donations to the hurricane relief effort thus far, more than half is from online donations, according to Ryland Dodge, an ARC spokesperson.

"Online giving is on the rise in general," said AmeriCares spokesperson Ashley Cross, whose organization also saw a significant increase in online donations following Katrina. For the Stamford, Conn., nonprofit disaster relief organization, the online response was enough to dwarf past relief efforts.

"In the past eight days, starting August 30, we've received $2.3 million in online donations," said Cross. "Compared to the tsunami, for instance, where we received $1.4 million online. That is a significant difference."

Todd Hendricks, vice president of development and direct response at the American Society for the Prevention of Cruelty to Animals (ASPCA), in New York City, said he believes the upswing in online giving is a credit to the American public. "(The hurricane) happened so recently, nobody's really had a chance to (set up a fundraising campaign) for it," said Hendricks."People are coining to us."

"Within the first 72 hours, we raised over $2.5 million in online giving. In overall giving: $3 million," added Hendricks. "That's more than we raised all year to date online."

According to a spokesperson for the ASPCA, by Tuesday evening the online figure increased to $2.9 million, with overall giving at $3.6 million.

To further delineate the extent of the charitable giving in response to Katrina, Hendricks recalled what followed the tragedies of September 11, 2001, when the organization ultimately raised more than $50 million. So vast and copious is the influx of online donations that some organizations have yet to find the time to process the figures. "The (online) response has been very, very strong," said Sheila Consaul, director of media relations at the United Way of America in Alexandria, Va. "(Online donations) are coming in so fast and furiously that we haven't been able to tally it all yet."

For Habitat for Humanity in Americus, Ga., the response online during the week after the storm was tremendous. "We've been receiving donation inquiries from here and around the world," said Duane Bates, manager of public/media relations. "As of last Friday (Sept. 2), we estimated $2.7 million in online donations." That number is more than four times the amount the organization has raised thus far in other forms of gift.