But it's worth checking out, because beneath its glitzy user interface are some cool experiments that could easily be implemented on a more plain-Jane search site. I like the "shelf" on Tafiti, where you can drag search results that you want to save or look at later. And I like the stack of search queries that Tafiti collects as you use the site; other engines record your search histories, but Tafiti shows us it can be done better.
More prosaic (but still pretty) features include a secondary "filter" field that lets you easily winnow down search results and different display formatting for results from the Web, books, news sites, and RSS feeds. There are also "blog this" and "e-mail this" options for results you save on your shelf.
There's also a highly experimental--borderline silly--"tree view" of search results. This view goes into my running list of weirdo search technologies.
Tafiti is a Microsoft open experiment, not a Google killer. But Google should take notice: With Tafiti, Microsoft is telling us that a search site can be useful without being dull.