Blinkx - Kenjin Lives again!
A new search engine blinkx is getting a lot of publicity now as a potential 'Google Killer'. A BBC article does a good job of putting it into context as a personal KM tool. What sets it apart is that it indexes e-mail and your hard-drive as well as the web. I've been experimenting with similar tools for some time and currently use Enfish, but this could tempt me to swap.

Like Kenjin, Blinkx watches what you're working on and suggests relevant links to e.g. what you're writing in a word processor. I found this rather distracting in Kenjin - possibly because following links is generally far more interesting than finishing a report - but Blinkx seems to do it more discretely.

It's only a Beta, so I don't want to judge too early as the results it gives currently far from Google-quality. Another downside is that it requires an installation to work which makes switching less simple than, say, defecting from Yahoo to Google search. But once switched, the lock-in is much stronger.

Also check out the Visualiser - looks like 'The Brain' software, but the way it grows as it continues to search is funky.