Google's effort, until now secret, is arguably the most ambitious of the three. According to sources familiar with the plan, the search giant is courting broadcasters and cable networks with a new technology that would do for television what it has already done for the Internet: sort through and reveal needles of video clips from within the haystack archives of major network TV shows.

The effort comes on top of Google's plans to create a multimedia search engine for Internet-only video that it will likely introduce next year, according to sources familiar with the company's plans. In recent weeks, Mountain View, Calif.-based Google has demonstrated new technology to a handful of major TV broadcasters in an attempt to forge alliances and develop business models for a TV-searchable database on the Web, those sources say.

"Google's trying to bring TV to the Web the same way they're bringing books to the Web," according to a media executive who asked to remain anonymous.

Google declined to comment for this report.

While Google is immediately aiming to cater to the broadband market, Microsoft has its sights on the interactive TV market for cable providers, being ushered in by convergence devices like its Microsoft Media Center PC software. It is building technology that will let people with a Media Center PC or Internet-connected TV comb through and find specific video files available over the Internet, broadcast and video-on-demand networks, according to a source. The software giant is expected to showcase the technology at the Consumer Electronics Show (CES) in January, the source said.

Yahoo is picking lower-hanging fruit. The Sunnyvale, Calif.-based Web portal is planning to introduce a multimedia search engine and is working with Web entertainment and news aggregators to index video clips that are already online. According to one source, the company plans to introduce its service in the first quarter of 2005.

America Online also will be a player in audio and video search. Earlier this year, the company bought audio-search company Singingfish.

Video is in the spotlight as the Internet begins to mature into an entertainment platform and becomes a viable companion for television, convergence devices that combine PC and TV features, and the networked home. As nearly 30 million US households get wired with broadband Internet, more people are getting comfortable using multimedia online, giving TV audiences more choices than ever about how and when they consume programming.

That's poised to open up access to vast new video libraries that will require new search technology to organise and make content relevant to viewers, much like Internet search engines have made sense of billions of disorganised Web pages.

Cable operators, phone companies and satellite companies are also upping the ante for video, bringing interactive, on-demand services to the television through enhanced set-top boxes, personal digital video recorders and convergence PCs.

Search is the glue that will one day bind these services and help consumers navigate the increasing amount of available content, media executives say. Already interactive programming guide makers have moved to make search more advanced, and companies like Comcast are beginning to sign up for those services. Comcast recently inked a partnership with Microsoft's ITV division to use its interactive programming guides.

For Google, Yahoo and even AOL, offering searchable video is an extremely attractive new market because it not only keeps them relevant to consumers hungry for multimedia, but it helps them appeal to brand advertisers, which spend about US$60 billion annually on commercials. Major TV advertisers are comfortable with the effects of commercials, and they're likely to wake up to Internet opportunities once on-demand video is ubiquitous.

Still, navigating the complexities of broadcast will likely be a significant challenge for Google and others in search. Business models for broadcasters online vary widely, and securing broadcasting rights over broadband could be sticky.

For example, if Google and Yahoo want to host and play video from their Web sites they must clear those digital rights with broadcasters. And broadcasters themselves must secure Internet rights with actors, producers and musicians, as well as clear spectrum signal rights with affiliates.

Being careful of existing business models is an issue, too. For example, CBS News offers video for free online, while ABC News offers subscription and paid video services for the likes of AOL and SBC Yahoo. CBS may want to boost traffic in order to sell advertising, but ABC may want to promote its subscription services via video search.

Search technology also must make vast improvements in order to find relevant audio and video. Currently a Web surfer inputs a search query into an engine to receive thousands upon thousands of results, and most people abandon the site if they don't find what they're looking for in the first 10 listings. But with clips of audio and video, that discernment will only increase, because each clip might be 15 seconds to several minutes.

The Goog tube
Google's project for TV search is ultra-secretive; only a handful of broadcast executives have seen it demonstrated so far. To build the service, the company is recording live TV shows and indexing the related closed-caption text of the programming. It uses the text to identify themes, concepts and relevant keywords for video so they can be triggers for searching.