You can also get flax seed oil. However: Oil contains little or no dietary fiber -- anti-cancer lignans are in the fiber; oil is more expensive than seed; and oil is lower in Omega 3s.
Here is a website to give you more info on flax seed or you can just Google it: http://www.goldenflax.com/flax-seed-oil.html
Also, check out www.hodgsonmill.com for info and recipes. That's the brand I use.
Sooooo.......slip some flax seed into your recipes!