Don't eat that beet, vegan Pete. It's alive, too.

Please excuse the corny headline. I just thought something cheesy would be the best attention-getter for an article about food. Yes, I'm going to milk the food puns for all they're worth. Anyhow, here's some guilt-free food for thought - Natalie Angier of The New York Times blurs the lines in the ethical food debate:

Before we cede the entire moral penthouse to "committed vegetarians" and "strong ethical vegans," we might consider that plants no more aspire to being stir-fried in a wok than a hog aspires to being peppercorn-studded in my Christmas clay pot. This is not meant as a trite argument or a chuckled aside. Plants are lively and seek to keep it that way. The more that scientists learn about the complexity of plants -- their keen sensitivity to the environment, the speed with which they react to changes in the environment, and the extraordinary number of tricks that plants will rally to fight off attackers and solicit help from afar -- the more impressed researchers become, and the less easily we can dismiss plants as so much fiberfill backdrop, passive sunlight collectors on which deer, antelope and vegans can conveniently graze. It's time for a green revolution, a reseeding of our stubborn animal minds.
[...]
"Plants are not static or silly," said Monika Hilker of the Institute of Biology at the Free University of Berlin. "They respond to tactile cues, they recognize different wavelengths of light, they listen to chemical signals, they can even talk" through chemical signals. Touch, sight, hearing, speech. "These are sensory modalities and abilities we normally think of as only being in animals," Dr. Hilker said.

Fair points. Vegans and vegetarians don't often acknowledge that they, too, are eating living things that "want" to live at least as much as "lower" animals. Perhaps the only morally defensible diet is Fruititarianism - that is, dining only on the parts of plants that can be removed without killing them.
At any rate, you can read the rest of Angier's article here.