A new report by JupiterResearch estimates that $128 billion in travel will be spent online in the United States in 2011.

The study, titled "US Travel Forecast, 2006 to 2011," also predicts that 38 percent of travel revenue will be made online in 2011. Higher fares and more people flying will be the main drivers of the increase in total online air travel revenue, which will grow from $49 billion this year to $72 billion by 2011, according Jupiter.

"Online travel revenue will continue to grow strongly from $85 billion in 2006," said Diane Clarkson, analyst at JupiterResearch and lead author of the report. "Factors that will spur online spending are greater consumer wallet share, increasingly sophisticated products available online, and improved online compliance in business travel."

The report also predicts that hotel reservations will continue to move away from the telephone, as more customers make their reservations online.