grep question

[Coran Fisher aka The Doctor]

I have a silly question on grep usage.  I'm interested in a way for 
grep to search the content of files in directory chains. I was wondering
if someone could clue me in on a way to do this either with a switch I haven't
figured out or by piping if necessary.  I have used find piped with grep to
search for files so I am aware of this particular ability.

Thanks!
Coran