"Any ideas on how to convince my 18-month-old that fruits and veggies are not a tool of the devil?? He ate pretty much anything we put in front of him up until a few months ago. Now his diet is becoming increasingly limited. Loves cheese, yogurt and bread related items and will tolerate the occasional banana and applesauce. I'm running out of ideas in how to prepare veggies to tempt him to try it. He's also been known to chuck fruit back at us as well. Any thoughts on making them more appetizing to toddlers or am I doomed to just wait out this phase??"
Since 18 months is all about asserting control, I don't think you're going to be able to convince him to eat anything you want him to. Instead, you're going to have to con him or trick him into eating vegetables.
You can con him by making a big deal about the delicious peas or carrots or whatever other vegetable you're eating, but talk about how it's only for "big kids" and little kids like him can't eat any. If you make it look and sounds really delicious and like it's something he really wants to do but can't, he may fall for the con and beg to eat some. If it works, ride the con 'til it's dead.
You could also trick him into eating vegetables and fruits by putting them into something else. I've known people who started making smoothies for their kids with yogurt and blended fruits. A friend had a muffin-crazy child who would eat anything in muffin form. So she'd just add vegetables to sweet muffins. It was disgusting, but her kid loved them. Spinach-banana muffins, sweet potato-apple muffins (which actually sounds kind of good to me), zucchini-chocolate chip muffins, green pepper-raisin muffins, etc. You could also try pancakes, which are just as deliciously starchy as muffins are and can hide all kinds of vegetables (mmmm...forbidden broccoli pancakes).
Now none of this might work. But by the time you've gone through all the ideas (and I'm hoping some commenters will have some other ideas) a month or two will have elapsed and maybe your son will become vulnerable to peer pressure ("Sophia's eating peas! Why don't you eat some peas, too?"). Or maybe he'll be past the horrible 18-month control-freak stage and into the delightful 2-year-old stage and will eat whatever you and your partner are eating. Or maybe you'll start drinking more wine with dinner and it won't matter to you anymore.
At any rate, eventually this stage will pass, and he'll eat fruits and vegetables again. And then he'll stop eating them again, and then start, and then stop, etc. And then he'll go away to college and it won't be your problem anymore. So do the best you can, but don't let it become an emotional issue for you or else it'll take on too much importance and will stress you out for no reason.