Tool to easily block Internet access completely for Windows?

I would like to block Internet access for my own machine. This is so that no apps can talk to the outside in the time frame I want it to. I know a firewall can do this but I don't want to install one. I don't want to use the included one. I know also I can change the gateway but that involves several clicks. I am looking for a system tray software or simple desktop app to toggle the access. On/Off with a single click.

You don't specify whether you need local connectivity as well. If you don't, the so-simple-someone-could-easily-overlook-it, 100% foolproof solution is to just unplug the network cable.

In Windows 7 it's just

ipconfig /release

and

ipconfig /renew