This one's just for fun... and topical as it's pretty late here in Vancouver.
Decaffeinated coffee plants, pest-resistant cotton, and Vitamin A-producing rice varieties have all been developed by introducing genes into plants. Scientists also create modified plants to identify and characterize the functions of specific genes. The current issue of Cold Spring Harbor Protocols includes a set of techniques for the creation of transgenic plants.
I hope someone passes a law forbidding the cultivation of these caffeine-less coffee plants outside of the lab because I'm not ready for the panic that would ensue if the crippled coffee ran wild.