Field to Field Settings?

Is there a way to use an already existing data set for an option when creating a New Custom Field? I do not see this under the "Field Type" menu, nor could I find it in the Help tool, so I wanted to send this off to ask.

This would be extremely beneficial if you've already selected values for another data set (Account Names, for instance) to be the populated data for a new field you wanted to custom create (Referred By, for instance. Have the names of accounts you've already entered into the system populate this new field).

Thanks!

Kris
Kris Thomason