Yammer, the Techcrunch50 "Best in Show" winner has announced the release of their API. The "Twitter for Enterprises," Yammer will likely see a big uptake in use thanks to the integration of tools the API will foster. Already, Seesmic has announced they will use the API to add twhirl support for Yammer. thwhirl is a desktop client that allows cross-posting to other microblogging sites and the ability to search for tweets, among other capabilities.
Yammer works just like Twitter, except that it's meant for internal corporate communications. You sign up with your company email, then can follow your colleagues. Yammer makes money by charging a fee for businesses to "claim" their users - gaining administrative control over them.
It's sure to be a desirable tool for businesses. In the first day alone, 10,000 individuals and 2,000 orgainizations signed up for Yammer. If you thought having a Blackberry linked to your work email was overbearing, wait until you're getting "Yammered" all hours of the day and night. And in addition to the Blackberry, Yammer has applications for the iPhone and a desktop client.