Phoenix Labs publishes a tool called Peer Guardian which will filter incoming connections from "known bad hosts" (RIAA, MPAA, malware, spamware, etc) and deny them from connecting to your computer.

It's a great tool that I highly recommend; ESPECIALLY the option which allows you to allow all "web" requests (connecting to websites from your browser) while still blocking them from connecting to your system.

The tool is free, and is quite easy to configure:
Once installed, open the application and select the "Allow HTTP" button on the right side of the page. Now, select the "settings" tab and "de tick" the "show allowed connections".

In the history area, you should likely either set a very LOW log level, or prune it all together:
Select "Remove" from the dropdown, and set "Every Days" to whatever you're comfortable with. Me, I have it set to 1 days as I really don't care about the logs at all.

From here, you're done configuring, simply click the "x" to close the program (it'll minimize to your system tray; this is ormal behavior as it is still runing, protecting your system.