"What is very likely to be present before 2016 would be a multi-sensual experience of virtual sex," said Julia Heiman, director of the Kinsey Institute for Research in Sex, Gender and Reproduction at Indiana University, Bloomington.
"There is a possibility of developing erotic materials for yourself that would allow you to create a partner of certain dimensions and qualities, the partner saying certain things in that interaction, certain things happening in that interaction."
A field dubbed "teledildonics" already allows people at two remote computers to manipulate electronic devices such as a vibrator at the other end for sexual purposes.
"People who use it are just blown away," said Steve Rhodes, president of Sinulate Entertainment, which has sold thousands of Internet-connected sex devices over the past three years. "This is not something that just the lunatic fringe does."
Gina Lynn, who writes the "Sex Drive" column for Wired magazine, says she has used and enjoyed the Sinulator and says there is no reason to fear the technology.
"People are still really afraid of...any sort of combination of sex and technology and of the Internet," she said. "What people are missing here is the point, which is the human connection that we are facilitating through the technology."
"No one who is even inventing this stuff wants or even thinks that technology could ever replace human connection or sex."
Annie Sprinkle, a former adult film actress, prostitute and author of "Spectacular Sex," said teledildonics are a logical outgrowth of improvements in pleasure devices.
"Now people use vibrators like mad and rightly so; the technology of sex toys has vastly improved," she said. "The more options the better; I mean it can never replace body to body."
"Some people will love it more than anything else and others won't be into it."
Entrepreneurs are also seeking to fuse explicit video imagery with real-life tactile sensation.
Brad Abram, president of XStream3D Multimedia, said his firm's "Virtually Jenna," an online game in which the player has sex with realistic cartoon of porn star Jenna Jameson, can link hardware devices following the action to genitalia.
"None of the big publishers will probably venture in there so we could be like the Hustler or the Playboy or whatever, the Penthouse of adult gaming," the Vancouver, Canada-based Abram said. "Sex toys is a huge business."
His service, without the hardware, costs $29.95 a month, and he said several hundred thousand people have tried the online sex game to date. He expects the hardware area of such simulations to grow rapidly.
Is it possible to go a step further and come up with a sex robot such as that portrayed by actor Jude Law in the 2001 film "AI: Artificial Intelligence" or the orgasmatron machine of the 1973 Woody Allen movie "Sleeper?"
Carl DiSalvo, a doctoral candidate at Carnegie Mellon University's School of Design, has helped design a robotic device that simulates the warmth and feeling of a hug. He said such work could be expanded into the realm of sex.
"That hardly seems to be difficult," he said. But "a realistic encounter is where the thing gets to be much more expensive."
Companies such as realdoll.com sell very lifelike human-size sex dolls without electronics for $6,500, not including $500 shipping. DiSalvo is skeptical about the demand for such high-end devices, as is San Francisco sexologist Carol Queen.
"I do find that a world full of people getting it on with you know, perfect gizmos instead of each other has some sort of a post-Orwellian kind of sense to it," she said. "I don't really think that most people are going to want this."
Others suspect the technology is also far off. "Right now they are having trouble making robots that just sweep floors," said Pepper Schwartz, a sociology professor at the University of Washington in Seattle and author of many books on sex.
"You know, we're talking about a big jump from something saying 'You are so sexy, I want you' to mimicking all the things that would create a cyborg. We're not at the cyborg level yet."
Going even a level further, other researchers say in decades to come advanced devices will be able to stimulate the brain to create a sexual experience without manipulating genitalia.
Marvin Minsky, a pioneer in the study of artificial intelligence dating back to 1951, said such devices could either trigger an actual physical response from the brain, or have the entire experience take place in the mind with the sensation of sex -- but without the mess or risk of sexually transmitted disease.
"It's bound to happen ... and is not as far off as some people think," Minsky, a professor emeritus at MIT, said of direct brain manipulation. "They are doing things with monkeys but it is not a big world-class industry yet, so that could take 20-30 years."
"But if the game (industry) people got involved in some underdeveloped country that didn't have any laws against it, it could all happen twice as fast."
Some researchers warn that too much fantasy could prove adverse to everyday human interaction.
"There is a great deal of pushing people out of social relations into a kind of simulated relationship, which in fact decreases what is essential in human life, which is sociability -- one's capacity to relate to other people," said John Gagnon, a veteran researcher and author on many books on sexuality.
