Here is a list of the FREE keyword research tools I used before:

1. Google Keyword Tool - https://adwords.google.com/select/KeywordToolExternal
2. Google Search Based Keyword Tool - Search-based keyword tool
3. WordTracker Free Keyword Suggestion Tool - Free Keyword Suggestion Tool from Wordtracker
4. DigitalPoint Keyword Sugestion Tool - Free Keyword Suggestion Tool (Wordtracker Suggestion Tool & Overture Bid Tool Combined) & Keyword Generator
5. Miva Keyword Tool - https://account.uk.miva.com/advertis...wordGenBox.asp

Anyone know somemore good one can share? Thanks