k1wi: Anyone in a household that is sharing a single broadband connection with a datacap between more than a single user/computer should consider reading this article:
http://www.anandtech.com/show/3715/family-proxy
You will notice a significant reduction, particularly in your HTTP traffic or any software updates you undertake across more than one PC.
I've got a transparent squid proxy setup at home, it's not a saving grace by any means given most web content is dynamic
Stat's from this mornings calamaris:
# Incoming TCP-requests by status
status request % sec/req Byte % kB/sec
------------------------------ --------- ------ ------- -------- ------ -------
HIT 1595 9.62 0.04 34783245 1.25 583.10
TCP_HIT 759 4.58 0.05 31342266 1.13 798.93
TCP_IMS_HIT 475 2.86 0.02 200549 0.01 18.73
TCP_MEM_HIT 292 1.76 0.02 3215698 0.12 453.41
TCP_NEGATIVE_HIT 69 0.42 0.04 24732 0.00 9.44
MISS 14976 90.28 1.84 2686524K 98.75 97.30
TCP_MISS 14761 88.99 1.86 2681480K 98.56 97.64
TCP_REFRESH_UNMODIFIED 179 1.08 0.47 3718430 0.13 43.03
TCP_REFRESH_MODIFIED 25 0.15 1.45 325181 0.01 8.75
TCP_CLIENT_REFRESH_MISS 11 0.07 2.64 1121128 0.04 37.74
ERROR 17 0.10 0.01 35772 0.00 399.70
NONE 16 0.10 0.00 33324 0.00 1595.24
TCP_MISS 1 0.01 0.07 2448 0.00 35.68
------------------------------ --------- ------ ------- -------- ------ -------
Sum 16588 100.00 1.67 2720527K 100.00 98.32
Getting close to 10% hit rate
And my refresh patterns fyi
refresh_pattern ^ftp: 144000 20% 1008000
refresh_pattern -i \.(gif|png|jpg|jpeg|ico|bmp)$ 260000 90% 260009 override-expire
refresh_pattern -i \.(iso|avi|wav|mp3|mp4|mpeg|swf|flv|x-flv|mpg|wma|ogg|wmv|asx|asf)$ 260000 90% 260009 override-expire
refresh_pattern -i \.(deb|rpm|exe|zip|tar|tgz|ram|rar|bin|ppt|doc|tiff|pdf|uxx)$ 260000 90% 260009 override-expire
refresh_pattern -i \.index.(html|htm)$ 1440 90% 40320
refresh_pattern -i \.(html|htm|css|js)$ 1440 90% 40320
refresh_pattern (cgi-bin|\?) 0 0% 0
refresh_pattern . 0 20% 4320