As the word itself suggest to locate files maybe you can install
locate commands, from the original GNU findutils (code here), or from the new implementation Debian squeeze from here (on the right side the link to the sources).
To locate only the binary, source, and manual page files for a command you can always use whereis, remembering that whereis has a hard-coded path, so may not always find what you're looking for.
The whereis command is part of the util-linux package and is available
which instead locate a command and returns the pathnames of the files (or links) which would be executed in the current environment, by searching the PATH for executable files matching the names of the arguments.
If used with
-a option it will print all matching pathnames of each argument.
Less efficient in terms of time, more slow because there isn't a database, it can result more efficient in terms of solution proposed.
Locate needs that the database is updated, (run
updatedb frequently), if not you will have a partial or wrong result. Moreover it's possible that some extensions or directories are excluded from the database (see
If you are searching only for a databased one you can see some project for desktop as Nepomuk, Strigi, Soprano KDE, Virtuoso and Akonadi, but even Deskbar-applet, Beegle for Gnome. They are somehow similar to the discontinued Google Desktop.
Some of the database systems can be used from command line too.