Install Squid 3 on uBuntu

#apt-get install squid3

Edit your squid.conf in /etc/squid3/squid.conf

http_port xxxx transparent #change xxxx with port number
cache_mgr Spearcross
visible_hostname Spearcross.net
cache_mem 64 MB
logformat combined %>a %ui %un [%tl] "%rm %ru HTTP/%rv" %Hs %h" "%{User-Agent}>h" %Ss:%Sh
access_log /var/log/squid3/access.log squid
cache_store_log none
cache_log /var/log/squid3/cache.log

acl apache rep_header Server ^Apache

cache_dir ufs /var/spool/squid3 5000 8 256
#For cache_dir use this formula
#(((x / y) / 256) / 256) * 2 = # Directory number
#example: you allocating 2GB for cache and 20KB average object size
#(((5.000.000 / 20) / 256) / 256) * 2 = 8
#so you write cache_dir like this
#
#cache_dir 5000 8 256

maximum_object_size 4194240 KB
maximum_object_size_in_memory 512 KB
negative_ttl 2 minutes half_closed_clients off

For Anonymous Proxy :

forwarded_for off
request_header_access Allow allow all
request_header_access Authorization allow all
request_header_access WWW-Authenticate allow all
request_header_access Proxy-Authorization allow all
request_header_access Proxy-Authenticate allow all
request_header_access Cache-Control allow all
request_header_access Content-Encoding allow all
request_header_access Content-Length allow all
request_header_access Content-Type allow all
request_header_access Date allow all
request_header_access Expires allow all
request_header_access Host allow all
request_header_access If-Modified-Since allow all
request_header_access Last-Modified allow all
request_header_access Location allow all
request_header_access Pragma allow all
request_header_access Accept allow all
request_header_access Accept-Charset allow all
request_header_access Accept-Encoding allow all
request_header_access Accept-Language allow all
request_header_access Content-Language allow all
request_header_access Mime-Version allow all
request_header_access Retry-After allow all
request_header_access Title allow all
request_header_access Connection allow all
request_header_access Proxy-Connection allow all
request_header_access User-Agent allow all
request_header_access Cookie allow all
request_header_access All deny all

Restart your Squid3

/etc/init.d/squid3 restart