This is rewrite of MTurk Extended HIT Search with some extra features. It now uses IndexedDB (http://en.wikipedia.org/wiki/Indexed_Database_API) to store the HITs.
It also implements some ideas from 'HIT history Check'-thread that use of IndexedDB made possible. See screenshots on userscripts page: MTurk HIT DataBase (http://userscripts.org/scripts/show/149548).
Other new features: pending/projected earnings (with progress bar), CSV export/import, requester notes and requester blocking (you can block specific HITs).
Current version is: 1.2 (2012-12-11)
Works on Firefox and latest Chrome (tested on 23.0.1271.64)