Switch to take mac online/offline

Hi!

I use a Mac mini as my entertainment center on my living room tv.

Also connected is a playstation, with wich I want to play online. If i want to do so, i firstly want to keep my mac from doing ANYTHING online. Not going to dropbox, not looking for updates, not downloads updates or podcast.

Is there a switch that can easily set the MAC to offline (ethernet+wifi) mode and then back to full online functionality with one click?

Any other ideas (not involving shutting the mac off )?

guess wifi on/off is the closest it'll get

thanks though!