Last night LA Start up Yammer took top honors at TechCrunch50.  What is Yammer?  It’s a Twitter-like application for businesses. Yammer aims to make companies more productive by making it easier for employees to communicate with one another. Unlike email which goes betweeno nly a few specified peole, on Yammer you can build a company network and have a Facebook, Friendfeed, Twitter-type experience within the organzation.

The purpose of Yammer is for co-workers exchange short frequent answers to one simple question: “What are you working on?” As employees answer this question, a company feed is created in one central location, enabling co-workers to discuss ideas, post news, ask questions, and share links and other information. The company feed can be accessed in real-time via the web, IM, SMS text messaging, an iPhone application, a Blackberry application, a desktop application, or email.

Yammer also serves as a company directory in which every employee has a profile and as a knowledge-base where past conversations are archived and easily searched.

Built by genealogy company Geni for their own employees, Yammer is now a stand alone service where  anyone with a corporate e-mail can sign up and create this social media application for their company. 

“There is such a huge demand for this type of service that 10,000 people and 2,000 organizations signed up for the service the first day it launched on Monday.   Anyone with a corporate email can sign up and follow other people in their company. But if a company wants to claim its users, and gain administrative control over them, they will have to pay. It’s a brilliant business model,” said TechCrunch in the announcement of the results.