You can totally clone tomatoes. The REALLY cool thing to do though, is "grafting". You can use the lower portion (basically short stump with root mass) of a hybrid plant (whose seeds are non viable) and 'attach' or 'graft on' the upper portion of an heirloom variety (whose seeds ARE viable). and make an awesome tomato! You get the strength, yield, disease resistance and other positive attributes from the lower and you get the taste, color and seeds of the upper! It's amazing to me that we, as humans can reverse engineer even a plant who has been genetically modified already! And doing it 100% naturally (yes, they do this with cannabis already).