One of the ways you can ensure that your employees are in sync is to maintain a robust, frequently published and widely used intranet. Important company messages benefit from significant repetition. Having an intranet can be a relatively cost-effective way to keep the company's message out there and ensure that all employees are working towards the same goals.
The intranet shouldn't be rigidly controlled. You will want to create and promulgate consistent brand standards, and give the site an inviting, readable feel. But people won't read the thing unless they have a stake in it.
Consider the ownership employees will feel in the intranet if they have the ability to publish their own branded newsletters, communicate with other departments and contribute to the front page "news" of the company. The intranet will become a destination for them--the first thing they read in the morning--that also means that the intranet will be a trusted source of
information.