Actually, I intentionally peel and cut the ends off onions, put them in a zip lock bag and store them at least over night in the fridge before using in salads. I think keeping them in the fridge helps to take away the "bite" of the raw onion and makes them sweeter. I especially like red onions in my salad. Any supposed harm from this practice is definitely a myth!
See my journal, The Balancing Act: Integrating Primal into My Life, for menu plans, musings, and more.