I had a meeting with a company I do quite a bit of work for lately, lets just say they buy and sell used machine parts. I've built them online applications that allows vendors from all over the country to sell them parts. Today I was able to tour their warehouse where they're receiving these parts and sorting them for re-sale or scrap. These parts are all invoiced online and marked with UPC tags generated and printed from the application I built for them. At the moment, they're still typing the codes into a computer to log them, but they're planning to be able to do this with scanning guns before long. It's amazing to see the reality of the whole system actually working, to see my tags on the parts in these orders. Very cool.