Proxy On/Off shows current proxy status (SOCKS, HTTP, HTTPS, FTP, Gopher) and allows quickly turn them and on/off.

Note: Do not try to verify that this widget works by looking into System Preferences. If you turn proxy on/off from the widget, you will not see the change in System Preferences. If you want to make sure that change did occur, use this command:
echo show State:/Network/Global/Proxies | scutil

Note: Changing proxy settings is considered to be a “privileged” operation. So you will be asked for the password once you have installed the widget.