Turn Off the Tivo Remote's Battery Eating Backlight

To turn the backlight off, press and hold the TIVO and the THUMBS DOWN buttons until the red light blinks three times, and then press CLEAR.

To turn the backlight on, press and hold the TIVO and the THUMBS UP buttons until the red light blinks three times, and then press ENTER.

I've jotted down a few other tips that you might be interested in and put them here.