The last three generations in America have been the first that you don't have to trade a good or service, for the same thing. We do trade money, and that is a good, however I am talking about trading wheat for potatoes, or auto work for home repairs. There is a lot to be gained in doing this right now.
I do this with my consulting services. For example, I wanted to learn about makeup. What type/colors to buy for myself, how to apply it, etc. I knew that knowledge in this area would save me time and money. It so happens that one of my friends is a professional makeup artist and has a bridal makeup business. She also has six kids that she has to feed - big grocery bill.
I asked her for a trade. She teaches me about makeup, I teach her about coupon shopping/frugal living. It has been great! She has been saving big on her grocery bill, and I am looking fab (if I do say so myself :). She has given me free makeup and can get me a 40% discount on professional makeup.
I have done this for other things as well. It is a great way to build friendships, help each other out, and save money.