In the film version of Minority Report, a personalized ad that knows about past purchases greets a character as he enters the Gap. Meanwhile, American Express ads tell Tom Cruise's own character that he looks like he needs an escape as he's chased by authorities.

Now Microsoft has filed for a patent that could eventually help make these advertising scenarios come true.

Microsoft has been investing heavily in advertising, including a $6 billion acquisition of aQuantive that should close this quarter, a new top ad exec at the company, and a new applied search and advertising research group.

"Techniques for the targeting of advertisements are meager," the patent application said. "Some industry experts question how long the old world approach can last before the entire system becomes impossible to justify."

The new Microsoft system, described in the patent application published last week, would be able to determine the identity of someone watching a display and deliver personalized ads to that person. Identification could come from biometric sensors, cameras, or more traditional login methods. A computer would then evaluate information that has been tracked about the person and the content and present a personally relevant advertisement.

The information being tracked could be very extensive, including but not limited to personal interests and hobbies, sex, age, location, profession, subscriptions, group membership, ethnicity, marital status, height, status in the family (i.e., parent or child), the viewer's address book, calendar, e-mail inbox, notes, purchasing history, and advertising preferences.

So, for example, the system could know that a man watching TV has a wife whose birthday is tomorrow, that the man has bought flowers for her birthday before, and what her name is. The targeted advertisement might create a virtual, photorealistic bouquet based on preferences and ask the viewer if he'd like to buy this bouquet for Julie's birthday tomorrow.

Such a system is bound to create privacy concerns, and Microsoft takes that into consideration, unlike in another recently published patent application regarding personalized ads for computer users. The new application mostly covers home devices, like cell phones, smart phones, PDAs, computer monitors, televisions, and projections, and does so with security of personal information in mind. "The tracking system may be located inside the person's home or at some other trusted location, so that the personal information stored therein is protected," it said. The system could also be tweaked so kids don't receive targeted ads.

There also seems to be a limit on how much information would ultimately get back to advertisers. The personalization would take place on the local system, rather than with the advertiser. "While the tracking system may notify an advertiser of the opportunity and request advertiser data, the advertiser is not aware to which person the advertisement is going to be presented, and therefore cannot personalize the advertisement at its end," the application reads.