LED Specialties sells ultraviolet blacklight flashlights with 51 LEDs. These are popular with pet owners who think they smell an odor in the house but can't find where it's coming from. Simply shining one of these on the carpet, all through the house (at night) will often reveal where their beloved pet tinkled. So instead of having to pay for the entire carpet to be cleaned, maybe they can just get by with cleaning up one or two spots!