One of the Web/telephony startups with the funny "J" name -- Jajah -- today cut a deal with the original Web-player-with-a-funny-name, Yahoo, to help deliver Web-based IP telephony calling to Yahoo's 97 million instant messenger customers.

The result is no joke for the incumbent telephony industry.

With landline penetration and revenue already eroding at a steady rate, the increased focus on voice telephony by one of the most maintream of Web portals, Yahoo, spells even greater competition. Competing with upstarts like Jajah, Jaxtr and Jangl and others is one thing; but facing IP telephony competition from Yahoo, Google (expected soon), Microsoft (already in the game with Office Communications Server; imagine VoIP integrated with the Office desktop suite too) and other major Web players is a different story.

Jajah said that Yahoo will use Jajah's newly-announced telephony managed service infrastructure, including network facilities, payment processing and customer care capabilities. Jajah claimed additional partnerships for its managed service offering with "landline operators, cable companies, mobile carriers and technology partners would be announced in the coming weeks, according to Frederik Hermann, Jajah's director of global marketing.

Yahoo has 97 million users of its instant messenger service; Jajah claims 10 million customers of its Web telephony offering.

Yahoo already offers PhoneIn and PhoneOut calling capabilities within its messenger product; the new partnership will move the infrastructure portion of the service over to Jajah.