Big corporations are often dismissed as dinosaurs. I'd agree, but argue that we're still in the middle of the Jurassic. There's a lot of benefits to being a massive organization, from economies of scale in manufacturing and marketing, to the depth of expertise you can build up in-house. The most important obstacle holding them back is the difficulty in getting that many people to efficiently organize themselves to achieve the business's goals. When I was at Apple I spent a large part of my time tracking down internal experts, to take advantage of the company's existing assets rather than wasting time and resources reinventing the wheel.
What I needed, and didn't have, was a complete and searchable directory of employees. I had the basic white pages, that listed a phone number, department, photo and immediate superior of any colleague, but nothing that let me track down people based on their skills or interests. That meant making connections was a time-consuming process, reliant on cold-calling and word-of-mouth. Multiply this across an organization, and you've got a massive amount of waste and inefficiency.
That's why I've been so interested in IBM's Bluebook project. They've built a company-wide system that's more like Facebook than the phone book. Each employee has a profile with their basic information, but also a wealth of user-generated content, from their resumes to blogs and things they've tagged. Searching this would let me locate helpful contacts a lot faster than more manual methods. They even encourage people who've been helped by specialists to rate them, so the helpers can get credit at their next review. This seems a crucial component of any system that aims to build horizontal connections in an organization. At the moment lip service is usually paid to the idea of helping other teams, but rewards are often based solely on your own group's achievements. This leads to fiefdoms and vertical silos within companies, as department heads fight to safeguard their resources from other groups. Only recognition of cross-team help can break that inefficient pattern.
Bluebook became the ancestor to Lotus Connections. I haven't seen much coverage of it in the mainstream tech world, but Connections seems to be getting a lot of adoption. I'm convinced that approaches like this are the key to getting more for less in big companies. Microsoft's Sharepoint is headed in the same direction with its approach to social networking using 'My Site' pages for each employee.
Part of winning the adoption battle might be to lose the social networking label, and focus on a more familiar analogy, the employee directory. It's easy to imagine how having an enhanced directory can help productivity, whereas a social directory makes it sound like you're providing a service for employees to waste time chatting on.