Free links can be attained via 1) Forum Signatures 2) Directory Submissions 3) Article Submissions 4) Social Bookmarking 5) Commenting on other blogs 6) Great Content for automatic linking
If you write a good article, other article sites and blogs will pick it up. I don't know if one article has ever gotten 1000 backlinks, but it can pull in a couple of dozen. If you mean free, without work too, I cannot help you.
If you are determined to get it for free, expect to spend a lot of time to get them. You might try out an automated blog poster, as seen below: http://www.commentkahuna.com/ (It's free!)
i agree with that too many backlinks at once you will get your site banned from google just do it step by step like medicalsupplies had mentioned don't get more than 100+ backlinks per day