Predicted technological advances may look great in the movies, but what about in your living room? Virtual think tank TechCast recently polled hundreds of futurists and technology analysts, and then calculated when emerging technologies are likely to be found in at least 30 percent of U.S. households or businesses. Here are its predictions for five familiar sci-fi scenarios. (Predictions carry a margin of error of plus or minus three years; results are not guaranteed.)

Biometric Security (predicted mainstream date: 2010)
As seen in the film "Minority Report"
In a few years, we'll be using fingerprint, voice, iris, or retinal scans to log on to Web sites and make purchases. Sounds a lot better than storing passwords under your keyboard, right? But remember: Your body is your password—so don't lose it.

The Holodeck (predicted mainstream date: 2016)
As seen in the TV show "Star Trek: The Next Generation"
The long-predicted virtual-reality revolution may finally be imminent, thanks to the popularity of 3D movies and of online worlds such as Second Life. A future "holodeck" could be enhanced by scents shot at your nose by a "smell cannon." Japanese researchers are working on the device now.
Self-Aware Computers (predicted mainstream date: 2019)
As seen in the film "2001: A Space Odyssey"
Though unlikely to turn murderous (in contrast to the late, lamented HAL 9000), machines driven by artificial intelligence will, within 15 years or so, be handling many routine tasks.

Domestic Robots (predicted mainstream date: 2020)
As seen in the TV show "Lost in Space"
Take a numba, Roomba. One technology expert predicts that by 2025 robots will outsell cars worldwide. So how will the ones without cars get to work?