Fastest free search engine listing

I've noticed over time that sometimes these forum post can hit the search engines pretty quick. What are some others ways to get quick search engine listing for backlinks?

 

use digg to get your site indexed by google.

your keyword will result on first page by using digg

 

Use a sitemap and submit it to google through google webmaster tools everytime you refresh the contents. That's a surefire way to tell the search engine-google to crawl your site. Or if you have a link in any of the high traffic site, your pages are instantly crawled and sometimes indexed...