Manage database from Firefox - SQLite Manager Extension
Firefox 2 got a Storage - database API baked by sqlite. It makes possible to operate any sqlite database from firefox programmatically. And finally someone created most exotic desktop SQLite Manager - XUL application, running in Firefox or XULRunner, needless to say it is crossplatform. Not that much features in current state (0.1.x), but does it really matter).
The pics:
SQLite Manager v.0.1.7 on Windows
SQLite Manager v.0.1.7 on Linux Fedora Core 4
Downloads etc