How can I get apt to use a proxy?

[Martin Maney]

I've been playing, mostly quite happily, with the preview release, and
as I'm looking to do some scratch installs on a few machines just to
see how well it handles them, I'd like to be able to have the 2nd stage
fetch the tens of MB of updates/additions through the local squid
proxy - it's faster and it saves everyone's bandwidth.  However, I
cannot find any way to get Ubuntu to set that up - I just tried, to no
avail, the "expert" install, which needed a lot more keystrokes but,
nope, it just blows straight out to the internet without a pause for
instruction.  Earlier I had tried setting up apt.conf, but that appeard
to get wiped out somewhere along the way.

Am I overlooking something or is this just missing?

Thanks!

-- 
Microsoft, which used to say all the time that the software business
was ruthlessly competitive, is now matched against a competitor whose
model of production and distribution is so much better that Microsoft
stands no chance of prevailing in the long run. They're simply trying
to scare people out of dealing with a competitor they can't buy,
can't intimidate and can't stop. -- Eben Moglen