[plug] Debian apt-get through a proxy

[Steve Grasso]

I've had a read of man and info, and searched Debian mailing list archives, but
can find no reference to configuring apt-get for use through a proxy firewall.
I'm sitting behind a fairly solid one here and am getting sick of fixing file
dependencies by hand. Any ideas?

And while I'm here (here's a dumb one) all of a sudden this box (debian slink
with KDE) has stopped firing up X for ordinary users. Accepts
username/password, blinks a few times and reverts back to KDE login screen.
I've had a poke around as root looking for stuffed X config files, permissions
etc and all appears to be normal. Again, any ideas?

Thanks.