Setup of squid cache to speed up my laptop

[jflinux]

So I keep 200 webpages open.
It takes forever to load all those webpages on 3Mbps DSL.
So I want to run squid cache on my laptop.

So I installed Squid cache.
Question1 : Which is the squid.conf I am using?
# locate squid.conf
/etc/init/squid.conf
/etc/squid/squid.conf
/etc/squid/squid.conf.original
/usr/share/doc/squid/examples/squid.conf
/var/lib/dpkg/info/squid.conffiles
/var/lib/dpkg/info/squid.config
# ps auxww | egrep squid
root 1666 0.0 0.0 22036 560 ? Ss 11:48 0:00 /usr/sbin/squid -D
proxy 1668 0.0 0.3 37940 18644 ? S 11:48 0:07 (squid) -D
root 5562 0.0 0.0 8952 868 pts/0 S+ 14:35 0:00 egrep squid

I want to modify the squid.conf, but there are many to chose???

Question2: Where is the squid cache directory?
If found it doing locate: /var/spool/squid
Most recent files seem to be going here: /var/spool/squid/00/0F

Question3: Why does the /var/log/squid/access.log have this over and over?
1309804455.603 0 127.0.0.1 TCP_NEGATIVE_HIT/500 294 GET http://img.tweetimag.es/i/danielpmaloney - NONE/- text/html
1309804455.606 0 127.0.0.1 TCP_NEGATIVE_HIT/500 294 GET http://img.tweetimag.es/i/danielpmaloney - NONE/- text/html
1309804455.609 0 127.0.0.1 TCP_NEGATIVE_HIT/500 294 GET http://img.tweetimag.es/i/danielpmaloney - NONE/- text/html
1309804455.612 0 127.0.0.1 TCP_NEGATIVE_HIT/500 294 GET http://img.tweetimag.es/i/danielpmaloney - NONE/- text/html
... repeats the above hundreds or more times.

Question4: Is there an environment variable to tell all browsers: opera, firefox, chromium
to use 127.0.0.1:3128 ? what line do I type in which file to set it?

Ok. I have it configured and running manually changing all my browsers to point at the proxy 127.0.0.1 port 3128 .
However, no speed improvement and a slight bit more swapping due to squid using some memory.
Looks like squid has zero benefit since the browsers have cache which does the same job.

Thanks!!