In this situation I would like to have a field for 'LIBOR.' I would like to be able to update this field once/wk, but ideally, I would like to be able to update it once, in one location, instead of having to do a mass update to every record. Does any functionality like this exist? Thanks!
I suggest creating a Custom Label
LIBOR with the value you intend to have in this field, and then adding a formula field on your object with a value of
VALUE($Label.LIBOR). This will allow you to update the value of the custom label and have the change reflected instantly across all of your records.
EDIT: You also need to use the VALUE() function so that you get the correct data type (number, not text), because label values are always text. It should look like this: