Yammer plugs partner apps into its business social network.

Yammer — a social network designed specifically for use inside businesses — will introduce a new “Activity Stream Ticker” that notifies colleagues when you perform certain actions. These actions include the use of applications from six new Yammer partners, including the Box.net file sharing service and the TripIT travel itinerary service.

In short, when employees using Yammer share a file via Box or plan a business trip on TripIt, this will show up in the ticker.

The new stream will complement the social network’s central activity feed. Much like the small feed Facebook recently added to the top right-hand corner of its user profiles, Yammer’s feed will not include comments and status updates — only employee actions.

“We’re making Yammer the superset of business data streams,” Yammer CEO David Sacks told Wired. “It’s pretty transformative to always have an ambient awareness of what your coworkers are doing.”

Earlier this year, Facebook integrated with the Spotify online music service, so that users who listen to Spotify automatically share their music choices with the Facebook friends. This becomes a way for users to discover new music and pass it on to others. Sacks hopes that the same sort of viral dissemination of information will occur with ideas and collaboration across the enterprise.

Yammer’s six application partners also include Expensify, a digital expense report manager; Spigit, a crowd sourced ideas moderator; TripIt, an online travel itinerary planning service; and Zendesk, a virtual help desk. Thanks to existing Yammer partnerships, NetSuite, SalesForce.com, and Microsoft SharePoint also appear in the Activity Stream Ticker.

Though Microsoft is partnering with Yammer — and despite its long history with Facebook — Box CEO Aaron Levie says that Yammer’s partner-friendly setup is exactly what you won’t get from Redmond — or Redwood Shores.

“This is the kind of innovation that you just literally can’t see from Microsoft or Oracle,” he told Wired. “They’re used to this vertical stack of software where you’re supposed to buy everything from them. And so they didn’t have to innovate because they had all these organizations locked in.

“Companies that forget about how to be a startup are the most ripe for disruption.”

Each partner feeds data into the new activity stream using Yammer’s open API, but IT managers overseeing the use Yammer will have the option of turning data on and off for each app.