transparent proxy

Someone could tell me how I can make a transparent proxy with the IPFW and the squid, it's a bit urgent. Thanks.

hi there, Im trying to get upsidedownternet working with arpspoofing, something along the lines of this: https://help.ubuntu.com/community/Upside-Down-TernetHowTo (but using arp spoofing instead of changing the targets gateway manually) anyway, ive got it semi-working, as some/most images that...