As technologies merge, everything old is new again. And for the right kind of startup -- one that can nurture a disruptive idea into potent new products and even entirely new markets -- vast amounts of capital await.

Indeed, investors are betting big on a range of emerging companies specializing in technologies that bridge the Internet, telecommunications and television.

Already, of course, the sector for such "convergence" tech players has produced a handful of stars and, for venture capitalists, lucrative exits. These include voice-over-Internet-protocol provider Skype Technologies SA, now owned by eBay Inc., and Jamdat Mobile Inc., which was bought in 2005 by Electronic Arts Inc. for $680 million a scant three months after the mobile game developer went public.

By the same token, convergence -- both as a concept and a set of technologies -- can be a sinkhole; witness the recent implosion of Amp'd Mobile Inc. Despite such setbacks, markets for these technologies are blooming, and investors are piling in.

Following is a rundown of the best-funded, privately held companies that play a part in driving convergence, ranging from aggressively promoted brand names for consumer video sites to less widely known software providers that make voice, audio, video and data available on a variety of devices. A few may go public, others will be acquired and some will flame out.

But dealmakers should take note: The tide of investment pouring into these players offers a sense of the scale and pace of innovation in these technologies.

Amp'd Mobile

The multimedia mobile phone content and service provider is a case study in uncontrolled growth, and it highlights the risks -- and hype -- surrounding convergence. The Los Angeles startup, which raised a whopping $350 million in venture capital in only two years, filed for bankruptcy protection in early June, although it expects to stay in business.

Hedge funds and strategic partners have joined venture firms such as Highland Capital Partners LLC of Lexington, Mass., Columbia Capital of Alexandria, Va., and Redpoint Ventures of Menlo Park, Calif., in its five rounds, including a $107 million deal in March. Amp'd says it has roughly 200,000 subscribers.

MobiTV

Portable TVs that pick up over-the-air programming never quite caught on, but MobiTV Inc. of Emeryville, Calif., is betting that consumers will use their mobile phones to pick up live digital television and radio programming. The company has raised $121 million from investors including Oak Investment Partners of Westport, Conn., and Menlo Ventures and Redpoint Ventures, both of Menlo Park, Calif. MobiTV has been delivering multimedia content to SprintPCS wireless customers for more than three years. Adobe Systems Inc. and Hearst Corp. are key partners and investors.

NexTone

While top competitor Acme Packet Inc. of Burlington, Mass., has already gone public, VoIP software developer NexTone Communications Inc. of Gaithersburg, Md., remains closely held. Private investors have poured $92.5 million into the company since it was founded, with two-thirds of that amount invested since late 2005. The session management software maker initially marketed its wares to telecom carriers but has since expanded its reach to include enterprises, allowing them to provide voice connections and related video-to-phone delivery services via the Internet.

Hands-On Mobile

The IPO market for mobile-phone game developers and publishers has already proven fruitful for Jamdat and Glu Mobile Inc. Another mobile game company to watch is Hands-On Mobile Inc. of San Francisco (formerly Mforma Group Inc.), which has collected $93 million over four years from investors including Bessemer Venture Partners of Wellesley Hills, Mass., Draper Fisher Jurvetson of Menlo Park, Calif., and General Catalyst Partners of Cambridge, Mass. Hands-On designs games for a variety of devices, including the popular BlackBerry.

Joost

Promising streaming video content from traditional TV networks, delivered on demand via PCs, Luxembourg's Joost Operations SA has raised $45 million in a single round that includes Sequoia Capital of Menlo Park, Calif., and Geneva's Index Ventures, along with media giants CBS Corp. and Viacom Inc., both of New York.

Unlike most Web video providers, Joost relies on peer-to-peer technology, drawing content from a network of users rather than from a centrally located server. Guided by Skype founders Niklas Zennström and Janus Friis, Joost reaps revenue from advertising. The company bolstered its management by naming consummate dealmaker Mike Volpi as CEO, who led more than 70 acquisitions in his 13 years at Cisco Systems Inc.

Brightcove

Online video distributor Brightcove Inc. has styled itself as both a "destination" Web site and a video publishing software platform for other sites, raising $81.2 million from investors over three years. Brightcove added three hedge funds to its investor group in January, building on early investments from the likes of Accel Partners of Palo Alto, Calif., and General Catalyst Partners of Cambridge, Mass.

SunRocket

Although it competes with better-known companies such as publicly traded (if beleaguered) Vonage Holdings Corp. of Holmdel, N.J., and Skype, VoIP provider SunRocket Inc. of Vienna, Va., has made headway in the burgeoning Internet telephony market. Promising complete calling services for a flat fee of $199 per year, SunRocket has signed up 200,000 customers. Since 2004, venture firms and other private investors, including international funds in Iceland and Finland, have invested about $80 million in three rounds.

Reef Point

Mobile phones that rely on cellular networks, Internet-based local area networks and fixed-line infrastructure are at the crux of so-called fixed mobile convergence. Reef Point Systems Inc. of Burlington, Mass., sells gateways that keep mobile devices connected across networks, allowing seamless roaming. Since a June 2006 recapitalization, the company has raised $46 million from investors including One Equity Partners LLC of New York, American Capital Technology Group of Bethesda, Md., and Jerusalem Venture Partners of Jerusalem, helping it keep pace with competitor and current IPO candidate Airvana Inc. of Chelmsford, Mass.

Ripe Digital

Specializing in digital content for younger, predominantly male audiences, Ripe Digital Entertainment of Hollywood, Calif., has been creating animation, sports and other video content for mobile phones and on-demand broadband networks since late 2005. A $38 million round of funding from Time Warner Investments and Rho Ventures, both of New York, and Columbia Capital of Alexandria, Va., last fall brought total investment in the company to $44 million, while a distribution deal with on-demand specialist TVN Entertainment Corp. brought Ripe's content to a wide range of users.

Podshow

PodShow Inc. of San Francisco is the world's largest distributor of podcasts, the equivalent of old-fashioned radio programs for portable music devices. Co-founded by a pair of music industry veterans, songwriter Ron Bloom and former MTV video jockey and Web design pioneer Adam Curry, PodShow hasn't raised as much money as other highly touted convergence plays. But its $24 million in two rounds of funding comes from top firms Kleiner Perkins Caufield & Byers of Menlo Park, Calif., and Sequoia Capital, along with Duff Ackerman & Goodrich Ventures of San Francisco and Sherpalo Ventures of Saratoga, Calif. The company provides a searchable directory of podcasts, as well as distribution tools for self-publishers.

See related chart: Bankrolling convergence