Thanks, guys. This forum is great!
arne: yes, squid is certainly running. It is listed during the startup procedure, and you can find it as a running process. Or, on my machine, you can just type the address of a large page (like slashdot), hit enter, and listen to the server's drive start to chatter.
davidbray and cc_skavenger: is there any significant difference between the two sets of commands you've given, IOW any reason I'd use one over the other?