Hotel chains including Mariott International and Starwood Hotels and Resorts have figured that if their rooms are going to go unfilled during the economic downturn, the empties can be put to another profitable use.

These and other hotel operators are setting up conference rooms with the latest in teleconferencing equipment so that companies don’t have to invest in the technology themselves, but can rent it by the hour.

Now, instead of flying workers across the country, a company will merely set up two or more convenient conferencing rooms and run the meeting virtually.

The benefits: No airfares, no hotel rooms, no restaurant meals, reduced time away from the office.

The going rate for these rooms runs about $500 an hour.

In many cases, hotel operators have partnered with tech companies like Dell and Cisco to equip the conference rooms.  So far, most rooms are located in major cities, but if travel budgets keep getting trimmed, the service could spread soon to smaller markets and more remote locations.

The fact that Cisco replaces one-time powerhouse General Motors on the elite list of U.S. corporations is a clue about the direction the economy and the markets are taking. Computer networking technology is replacing cars as one of the driving forces of the economy.

Being added to the Dow is “a tremendous honor … [but] very humbling,” Chambers told a group of international reporters today at the Cisco Partner Summit in Boston.

“GM is a great company, always a great customer, and a very very good partner,” Chambers said, adding that everybody at Cisco knows somebody at GM. “It’s an icon.”

Chambers prediction for the direction of high tech: Video will make up 90% of all network traffic in two years. Is your IT team prepared for that?