The article mentions that we don't usually send Easter cards because cards showing the crucifixion of Christ wouldn't be too pleasant. That might be a good reason not to send Good Friday cards, but Easter is about the rising of Jesus from the dead.

Good point. Christians celebrate the resurrection, not the crucifiction.

Christians do celebrate the crucifixion on Good Friday. This takes place the Friday before Easter. It is called "Good" Friday because of the wonderful thing God, in the person of Jesus, did for us by dying for our sins.

It is called Good Friday, but don't go so far as to claim that Christians "celebrate" it. They remember it, and keep it, but it's not time to par-TAY.

Just as you would remember someone who died sacrificing his life for others (like the firefighters and police at the world Trade Center) but it's not time to break out the bubbly! Kill those firefighters all over again, because it's time to boogie!