Tembo is a search tool based upon the Apple's Spotlight index and engine. The job of Tembo is to make searching (and finding) of files, mail messages, bookmarks, ... as easy as possible.
In a first pass, Tembo shows results grouped by type. For each group, Tembo lists the top 10 matches. Often enough you will find the sought for file right there.
You may also drill down into individual groups. There you will find filters appropriate for the current context. The Messages group, for example, offers filters on author, recipient and subject.
Thus Tembo is much more than a file search tool. It works as an extension to Apple Mail / iChat to locate messages. And as extension to Safari to search browsing history and bookmarks, etc.