I just came across a new competitive research tool by the name SEMRush. It's a new SEO tool for keyword and AdWords research developed by the team of SeoDigger and SEO Quake FireFox plugin.
SEMRush uses 25 million of the most popular and expensive keywords to collect Google search results. SEMRush can show you keywords for any domain ranked high enough to be in top 20 search results results or that purchases AdWords. The tool is based on the US version of Google.com.
• Identify your competitors
• See competitors’ organic and AdWords’ keywords, find their strengths and weaknesses
• Find their landing pages
• Discover your own long-tail keywords
• Check Google rankings of any site
• Calculate competitors’ costs for AdWords
• Search for potential advertisers
• Find potential vendors of traffic