This looks interesting: New Idea Engineering's SearchTracks uses Javascript to grab and analyze search queries executed through a variety of search tools, including:

• Verity K2
• Verity Ultraseek
• Hummingbird/Fulcrum
• Google Appliance

The queries are parsed, and the following tidbits are captured in a database:

• Search term(s) (normalized)
• Search terms (as entered)
• IP Address of the visitor making the request
• The sub-section of the site the search was performed over
• The number of results found (if available from the search engine)
• The total number of documents returned from the search (if available from the search engine)

From this data, SearchTracks generates a variety of search analytics reports (you can learn more and see some report samples here). SearchTracks also manages best bets (they call'em "directed results").

Good tool to know about!