source rpms

[nick.smith79 at gmail.com (Nick Smith)]

how can i get the source rpms for the packages installed on my centos
3.6 server? is there a certain repositories i have to add to my
yum.conf?  Im trying to setup a filtering program "smartfilter" and
they want me to point to the source for squid, which i cant seem to
find.  can anyone shed some light on this for me?  someone i was
talking to said that centos strips out the source to keep the bulk
down, but i was hoping that wasnt the case.

thanks for any help.

Nick