How to search for column reference in oracle

Imagine that you need to find out which code update a column in a table. Some developer tools could point out who refers to the table but so far I couldn't find the one that could answer my need.

All_source comes to the rescue, I'd say that it is a special view that holds all the database objects accessible by the user.

Here is the description on the view's columns:

OWNER	VARCHAR2(30)	NOT NULL	Owner of the object
NAME	VARCHAR2(30)	NOT NULL	Name of the object
TYPE	VARCHAR2(12)		Type of object: FUNCTION, JAVA SOURCE, PACKAGE, PACKAGE BODY, PROCEDURE, TRIGGER, TYPE, TYPE BODY
LINE	NUMBER	NOT NULL	Line number of this line of source
TEXT	VARCHAR2(4000)		Text source of the stored object

Example:
I need to find out who refers to column FK_USER.

select * from all_source where text like '%FK_USER%'

And I will get all the places which have reference to FK_USER.

If you would take it further, you could utilize it for searching almost anything (e.g. comments in the code, TODO tag, exception).

... wondering if there're more "magical" view like this.