Flaxseed is all but mainstream. Wal-Mart sells 8 ounces of organic flaxseed oil for around $5.50. There is an abundance of flaxseed oil products.
The superior product to flax seed and its oil is hemp seed. It has an even better ratio of omega-3 to omega-6. The problem is that it is more expensive. Flaxseed oil is often described as nutty, while hempseed oil is light and delicate. Hempseed oil is great for salad oil. I have just started using APV with hempseed oil.
Omega-3 is a big deal. If I did not have flaxseed oil, I would pick some up at Wal-Mart.