...seek back-links from, or submit content to...

1. Article Sites
2. Online Directories
3. Social Networks
4. Forums
5. Blogs
6. Document Sharing Sites
7. Video Syndication Sites
8. Image Sites
9. Pinging sites
10. Social Bookmarking sites
11. Search Engines
12. Other?

and what do you think of tools like

"GSA Search Engine ranker"
"No Hands Seo"

and are there any others that can better help you?

I'd be interested in your thoughts...