Check if TV is on or off

Hi everyone!
I'm looking for ideas on how to check if my TV is on or off using my arduino
I've searched around but haven't found anything

I'm working on a project of home automation and i'd like to be able to know if the tv is on or off

It's a 40" sony bravia

How about a current sensor on the mains input?

Some kind of light sensor mounted (eg. stuck to) the "on" power LED?

Also if the TV has a "video out" port (eg. composite video) a simple voltage detector might show if the TV is on because the active pin would be above ground potential.

As Mike suggested a current sensor like this maybe Non-Invasive Current Sensor - 30A - SEN-11005 - SparkFun Electronics

thanks everyone! I think the current sensor is the way to go as I don't have video out, if connect anything to audio out it silences audio on the TV and the USB port is in use so it's not an option.

I'm going to try something like this: Three Transistor Voltage Detector… | HACK A WEEK

That link says: "Three Transistor Voltage Detector"

Current isn't the same as voltage.

Just to throw it as an idea although current sensor aren't expensive…

Why not detect if your TV Toslink is emitting light or not ?