Meet the Crackle Tube: an interactive plasma lamp from Can You Imagine that puts on a show as you touch or play music around it. These are made in various colors. The Crackle Tube also has easily adjustable mirrors. There are two knobs that let you change patterns and audio sensitivity.
The above video shows the Crackle Tube in action. This is a rare item but you can find it on eBay from time to time.