The easiest and highly effective way to disguise your IPA from websites and prevent your ISP from seeing where you're going is to use TOR at
http://tor.freehaven.net Turn off Java and Java script and flush your cache and cookies before and after. It's also a good idea to prevent incoming ICMP packets(pings) in your firewall. Turn off Image loading and manually select pics if it's too slow for you.
Convience and Security have an inverse relationship.
For P2P, use Peer Guardian 2 and release and renew (change) your IPA, if it's static (unchanging) fairly frequently by going to the command prompt, typing ipconfig/release, then typing ipconfig/renew, wait for a new IPA to be established, cold boot and try again if unsuccessful the first time.
Downloaders of pirate files are at little risk of a bust, there's too many of us and the ISPs don't want to care, but it's wise to stay a moving target by changing one's address fairly often.