If you like to use aromatherapy while you work or surf on your home computer, you need a USB Aromatherapy Diffuser. The one in the image is from Sharper Image, and it requires you to use your own essential oils. You put a drop or two of the oils on the scent pad, place the pad in the diffuser, and plug it into a USB port. It has a sliding control switch for normal level / strong level / or off. The USB Aromatherapy Diffuser is $29.99 at Sharper Image. If you don’t have your own oils, and you’d like a better price, there’s a similar, highly user-rated Gaiam USB diffuser with a set of four 100% natural essential oils for $19.99 from Amazon.