In order to not get banned by using the same text color as the background, I came up with an idea. Have not tried this yet but I am certain it works. You make an image of 1 width and around 100 height with a color of whatever your background is. You then make a table or cell of a table with the background image and a background color of white and use css to repeat the background image on the x co-ordinate. Now use css to make the text the same color as the background. Easy as that, hidden text.
Enjoy your search engine safe, hidden text