Yahoo launched a new application called OneConnect for the iPhone that connects a long list of popular social networks and joins them together in one convenient interface. It’s available for free download in the App Store and also integrates instant messaging and short messaging into one application.

The “Pulse” feature in OneConnect lets users see a status list of their friends that pulls from social-networking applications including Facebook, MySpace, Twitter, Bebo, Friendster, and Flickr, among others. The list is populated chronologically, with the most recent update from a friend on any of the sites at the top.

“Rather than going to six sites, you need one click on Pulse in OneConnect,” said Macro Boerries, executive vice president of Yahoo’s Connected Life group, at the CTIA conference in San Francisco on Wednesday.

A separate Favorites list lets users get an update on just a handful of specific people, or all of your friends at once. It’s a convenience unique to the iPhone, as no PC utility exists to perform this function.

The OneConnect application was built using Blueprint, a development environment Yahoo first introduced earlier this year to allow developers to build applications that can work across a range of phones. Yahoo expects to offer OneConnect to users of other devices in the coming months.