A simple Spotlight front-end substitute. At present it's very simple: the only searches you can do are filename and content. But you can use wildcards or not, specify word-based, case-insensitive, and diacritic-insensitive searches, and construct complex searches with AND, OR, and NOT. You're shown the actual search query in Spotlight's native query language. Results are a simple list of filename and paths.

Requirements:
OS X 10.4
Universal Binary