Nick over at the Disruptor Monkey blog talks about how their FindaYoda feature has proved a surprise hit. This is a way of seeing who else has a lot of material with a keyword you're looking for, and its success backs up one of the hunches that's driving my work. I know from my own experience of working in a large tech company that there's an immense amount of wheel-reinventing going on just because it's so hard to find the right person to talk to.
As a practical example I know of at least four different image comparison tools that were written by different teams for use with automated testing, with pretty much identical requirements. One of the biggest ways I helped productivity was simply by being curious about what other people were working on and making connections when I heard about overlap.
One of the tools I'd love to have is a way to map keywords to people. It's one of the selling points of Krugle's enterprise code search engine. Once you can easily search the whole company's code you can see who else has worked with an API or algorithm. Trampoline systems aim to do something similar using a whole company's email store, they describe it as letting you discover knowledge assets. I'm trying to do something similar with my automatic tag generation for email.
It's not only useful for the people on the coal face, it's also a benefit that seems to resonate with managers. The amount and cost of the redundant effort is often clearer to them than to the folks doing the work. Since the executives are the ones who make the purchasing decisions, that should help the sales process.