SEO Tools Unlimited

I haven't touch about SEO for quite sometime. Maybe because I'm not on website development at this moment. So, to refresh my memory I looked around and I found this useful tools. I used to subscribe newsletter from this website but I didn't received any newsletter from them anymore. Anyway check out their SEO tools at

http://www.seochat.com/seo-tools/

And here is the list of the tools (I don't even know half of it):

1. Adsense Calculator
2. AdSense Preview
3. Advanced Meta Tag Generator
4. Alexa Rank Comparison Tool
5. Check Server Headers
6. Class C Checker
7. Code to Text Ratio
8. CPM Calculator
9. Domain Age Check
10. Domain Typo Generator
11. Future PageRank
12. Google Dance
13. Google Keyword Suggestions
14. Google Search for Multiple Datacenter
15. Google Suggest Scraper
16. Google vs Yahoo
17. Indexed Pages
18. Keyword Cloud
19. Keyword Density
20. Keyword Difficulty Check
21. Keyword Optimizer
22. Keyword Position Check for Multiple Datacenter
23. Keyword Typo Generator
24. Link Popularity
25. Link Price Calculator
26. Meta Analyzer
27. Meta Tag Generator
28. Multiple Datacenter Link Popularity Check
29. Overture Keyword Suggestions
30. Page Comparison
31. Page Size
32. PageRank Lookup
33. PageRank Search
34. Robots.txt Generator
35. ROI Calculator
36. Search Engine Comparison
37. Search Engine Keyword Position
38. Site Link Analyzer
39. Spider Simulator
40. URL Redirect Check
41. URL Rewriting

Now I wonder why my PR is undefined, null, void or blank???