Pfl

This package can be used to search for files (or strings) provided by packages that are not yet installed, and optionally installs a little cronjob to update the database on the internet with the information that is available to be queried.

Installation
You can install with the following command:

Usage
The database can be used online to search for files installed by ebuilds. Lets say you want to run glxgears but it isn't installed. Recently the program was removed from mesa itself, so you could search for glxgears online to find the related package: search online

search time comparison with equery
Here just a result of search times compared to equery

Pfl is much more quicker to search files (even if not installed locally), while equery is more powerful and gives more options to search.

External resources

 * PFL homepage