Gartner analysts are warning companies to be wary of investing in internal social networking. With Facebook poised to license its developer platform and several companies offering proprietary intranet-based social networking applications, Gartner’s analysts caution that social networking isn’t mature enough to warrant status as a critical business tool. VoiP and instant messaging are more beneficial, they say.

Over at IBM, the Blue Pages were an early stab at social network-like profiles. While you couldn’t actually socialize with other employees through the Blue Pages, you could find other employees without actually knowing their last names. A search for somebody who coded in C and spoke Tagalog would reveal a list of employees whose profiles matched those criteria. Adding the social networking element means you can now create networks of people who share common expertise, are engaged in similar work, or serve the same customers.

Communities of practice are a great idea but have been a bitch for most organizations to actually create. In a community of practice, people in an organization who do the same kind of job for different business units are able to share knowledge and network with one another. Think about, for instance, regulatory affairs. Distinct business units in large companies each have regulatory affairs professionals. They work alone or with incredibly small staffs. A community of practices makes it easy for all of these people to share ideas and seek counsel rather than work in isolation.

A social network would make it a breeze for those regulatory affairs professionals (or, say, organizational communicators) to form a group and stay connected.

Meanwhile, the news feeds would keep you up to date with the goings-on of colleagues (the equivalent of “friends” in public social networks)—what conferences they’ve been to, what projects they’re working on, when they’ve been promoted or moved to a new assignment.

While there are challenges to implementing social networks on intranets—like getting employees to populate their profiles with useful information and keep them current—the software tends to be low-cost and the benefits could be huge. In any case, they’re certainly more valuable than existing employee directories, which require you to know the name of the employee you’re searching and the information you get back is limited to phone number, mail stop, email address and maybe a reporting relationship.

Gartner’s got it wrong on this one.