AND... it isn't what you think. I am eyeing up a certain USB hub and it is telling me it is USB 2. Plus I don't need a power adapter if I don't use more than 100 mA for any single port. This is fine until I check out the details of my scanner, it reports 2.5 watts. How do I make sure the hub will handle the scanner and for that matter 2 ipod shuffles? Now I was told a formula to figure this out. Volts x amps = watts or Watts x Volts = amps This isn't my field of knowledge, so i'm hoping somebody here knows the answer to this. Now i know the amps, and basically I need to know if the 2.5 watts is higher than 100mA, if its under, I can buy the hub without an external power supply. Btw, I don't want the power supply to begin with, hence the issue here. I live in the UK and the electrical current is AC.