US TV networks rolled out their latest gimmicks as the presidential election results came in today.

CNN's Jessica Yellin declared it was like she "followed in the tradition of Princess Leia" as she was beamed into the studio as a hologram for her position in a tent at Barack Obama's election night party in Chicago.

A total of 35 high-definition cameras surrounded her in the CNN tent and worked in conjunction with the studio cameras in New York to show her talking to host Wolf Blitzer from the studio floor in the TV first at 7.15pm local time (12.15am GMT).

"It looks a little different from a real person there, but it's pretty remarkable," she said.

The gimmick worked much better than CNN's first on-screen use of a hologram showing the make-up of the US Senate and House of Representatives, which froze earlier in the evening.

The news channel also used a touch-screen exit poll counting machine in its election centre.

CNN was also the only network to set up a voter fraud hotline, which concerned Americans could call after spotting any trouble at the polls.

Other networks tried not to be outdone.

ABC converted New York's Times Square into an outdoor viewing party, much like its New Year's Eve extravaganza, but with less people.

NBC lit up a map under the ice rink at New York's Rockefeller Centre, turning states red or blue once the results were known.

Banners for Mr Obama and his rival John McCain rose 16 stories from the ground overlooking the rink.

America's Election HQ at Fox used a 12 by 12 electronic video cube which showed different scenes around the US on each side.