Pfl

Portage File List (PFL) can be Article description::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.

Emerge
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 but it isn't installed. Recently the program was removed from itself, so you could search for  online to find the related package: search online

Search time comparison with equery
Here is a result of search times compared to :

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