If you want to celebrate the 4th of July before Friday, we suggest the Blue Star Banner Plasma Globe. Put your fingers on the glass and its stars and lightning bolts will reach out to touch you, definitely less dangerous than your average firecracker.  While we have always liked plasma globes and wondered how they work, the Online Science site took away all the mystery in their description. We won’t spoil it for any scientifically challenged others, but you can pick one up for $39.99 without looking at the fine print.