Mine

http_port 3128
visible_hostname Gateway

# Configura��o do Cache
cache_mem 64 MB
maximum_object_size_in_memory 128 KB
maximum_object_size 30000 KB
minimum_object_size 0 KB
cache_swap_low 90
cache_swap_high 95
cache_dir ufs /var/spool/squid 30000 16 256
# Localiza��o do log de acessos do Squid
cache_access_log /var/log/squid/access.log

refresh_pattern ^ftp: 5 2% 2280
refresh_pattern ^gopher: 5 0% 2280
refresh_pattern . 5 20% 2280

acl all src 0.0.0.0/0.0.0.0
acl manager proto cache_object
acl localhost src 127.0.0.1/255.255.255.255
acl SSL_ports port 443 563
acl Safe_ports port 80 # http
acl Safe_ports port 25  # pop3
acl Safe_ports port 110 # smtp
acl Safe_ports port 4899 # radmin
acl Safe_ports port 21 # ftp
acl Safe_ports port 443 563 # https, snews
acl Safe_ports port 70 # gopher
acl Safe_ports port 210 # wais
acl Safe_ports port 1025-65535 # unregistered ports
acl Safe_ports port 280 # http-mgmt
acl Safe_ports port 488 # gss-http
acl Safe_ports port 591 # filemaker
acl Safe_ports port 777 # multiling http
acl Safe_ports port 901 # SWAT
acl purge method PURGE
acl CONNECT method CONNECT

acl msn dst 207.46.110.0/24 207.46.104.0/24 64.4.13.0/24
http_access deny msn

acl bloqmessenger url_regex www.e-messenger.net webmessenger.msn.com
http_access deny bloqmessenger

# bloqueia uma lista de dominios
acl proibidos url_regex -i "/etc/squid/proibidos"
http_access deny proibidos
http_access allow manager localhost
http_access deny manager
http_access allow purge localhost
http_access deny purge
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports


# Libera para a rede local
acl redelocal src 192.168.1.0/24
http_access allow localhost
http_access allow redelocal !msn

# Bloqueia acessos externos
http_access deny all

# Proxy transparente
httpd_accel_host virtual
httpd_accel_port 80
httpd_accel_with_proxy on
httpd_accel_uses_host_header on