Think Green! ;)

Here are some free online search engine tools:

Google Sets
A very cool tool to help you create keyword sets in the same family.

Hub Finder
This tool provides a good way to find backlink neighborhoods.

View Trend
Reports of your current and previous Google PageRank, Alexa Rank and incoming links for your website.

Keyword Density Analyzer
keyword density and word depth calculator

Keyword Suggestion Tool
This is a handy little tool will show you the results of your query from both Wordtracker and Overture for determining which phrases are searched most often.

Search Engine Script
Put Search Functionality On Your Website

Backlink Anchor Text Analyzer
Quality backlinks is one of the most important factors in Search Engine Optimization.

SiteReportCard
Provides detailed reports on various aspects of your web pages including: Broken Links, Misspelled Words, HTML Validation, Load Time Analysis, Meta Tag Optimization, Image Optimization, etc....

META Tag Analyzer
Using this tool you can: - See how search engine robots analyze your web site - Receive tips on how to improve your Meta Tags - Check the keywords used on the page and find the keyword density.

META Tag Generator
Wizzard that builds the meta tags for you. Here is another one.

More Search Engine Tools here