Most modern PCs come adorned with numerous USB sockets capable of connecting a wide range of devices. Printers, cameras, MP3 players all make use of the easy connectivity of USB so why not christmas decorations too?
These USB Christmas trees stand about 12cm high & will run from any computer with a spare USB port (or one that you are willing to do without your printer on for a while).
Once plugged in the computer will automatically engage it's much underused festive decoration recognition routines and light up the tree without need for batteries of mains cables.
The USB christmas trees flash about once a second, alternating in colours between red green blue and cyan (which we thought was just a posh word for blue anyway).