|To test, tonight remove the ethernet cable/usb modem.|
To be more energy consious you might also put all that computer stuff on a power strip. All wall warts and usb devices should be on that power strip. Turn it all off when you are not using it.
"Best Practices", Event viewer, host file, perfmon, antivirus, anti-spyware, Live CD's, backups, are in my top 10