Avid followers of politics who were watching the recent Democratic convention on a hotel room television might have noticed that Sen. Barack Obama had put on a few pounds. His face was rounder than it had looked in the past few months.

Actually, the senator is his same svelte self. What had changed was the television they were watching him on. Many of the nation's hotel chains are bowing to consumer pressure and replacing old picture tube TVs with new LCD and plasma flat screens, but most have failed to take that last step: adding high-definition service.

As a result, the widescreen high-definition-capable flat panels in many hotels often show standard-definition analog TV. To fill the screen, the old-style squarish images are stretched, resulting in wider-than-normal heads and bodies.

Stretching the image has another undesirable result: It reduces the image resolution, making the picture on the new flat-panel TV look worse than it would have on a standard picture tube set.

Popularity Is Behind Push

The industry is moving to flat-panel TVs because as more consumers buy them, they want the conveniences of their homes to be in their hotels. But hotels have been slow to install HDTV because of the cost.

Upgrading the servers that provide the video-on-demand programming, changing the devices that switch channels in each room (and allow guests to see their bills and check out), and updating in-room hardware and cabling could cost as much as $100,000 for every hotel property, said John Timmerman, vice president for operations at the Ritz-Carlton Hotel Co.

"With finite dollars to spend on upgrades, we get the most bang for our buck with in-room coffee, new shower heads and flat-panel TVs," Timmerman said.

The company began by offering 35-inch LG brand LCD sets in rooms. But as customers bought larger TVs for their homes, the chain upgraded as well. New rooms now have 37-inch models, with premier suites outfitted with 42-inch Bang & Olufsen sets.

At Hilton, all rooms will have flat-panel TVs and HDTV service by June. In addition, newly built hotels must make HDTV part of their offerings.

Among the other Hilton properties, Embassy Suites will have flat-panel TVs in suites by April. Doubletree and Hilton Garden Inn rooms will have HDTV by the end of 2009, and Homewood Suites by the end of 2010.

At Hyatt, 25,000 rooms, or 40 percent of its total, now have flat-panel sets, with 15,000 on order. Hyatt has also increased the size of its sets from 32 to 37 inches, with 42-inch plasma TVs in its suites. All rooms will have flat-panel TVs by early 2011. The company's moderately priced Hyatt Place and Hyatt Summerfield Suites brands use only flat-panel TVs and offer HDTV service in all rooms.

But for the rest of the Hyatt chain, even the more expensive properties, the company "has no road map for putting in HDTV at this time," said Larry Builta, vice president for engineering at Hyatt Hotels North America.

LodgeNet Serves 1.8 Million Rooms

Hotels often do not buy TV programming and equipment directly but do so through a third party. Hilton, Hyatt and Ritz-Carlton all use LodgeNet Interactive, which provides TV service to 1.8 million hotel rooms in the United States, about 40 percent of the nation's total number of rooms.

LodgeNet, which began offering high-definition service in 2005, has placed it in 130,000 hotel rooms and expects to add it to 500,000 rooms this year.

When installing standard-definition TV service, the company typically shoulders the hardware costs and then shares the video-on-demand revenue with the hotel. But the situation has become more complicated with HDTV.

"The demand for HD is so great, it is exceeding our available capital," said Scott Young, LodgeNet's president and chief marketing officer. "We are looking for new funding options." One possibility: the hotel would pay for the new equipment and LodgeNet would manage and support the service.

As hotels nationwide embrace the flat-panel TV, it brings an end to another part of hotel culture.

"We will have no more TVs in an armoire," a Ritz-Carlton spokeswoman said.