Research in Motion announced today that it is purchasing Chalk Media for $18.7 million. Chalk is the developer of Mobile Chalkboard, a mobile content platform and application suite that lets companies develop rich media "pushcasts" for BlackBerrys within organizations.

The pushcasts can include text, audio, and video data. They can also exist in the form of surveys and click-to-call e-mail requests, and stay resident on the devices so users can continue to access them even with no cellular data signal. It's primarily a business play here, as opposed to an end-user mobile content platform, but still worth keeping an eye on. The two companies expect the deal to finalize by February 2009.