Turn your WordPress site into the ultimate SEO tool! Monitor ranking progress, track your backlinks, analyze data from Google Webmaster Tools in your
Track your site's keyword performance in Google, Bing, and Yahoo! Track 10 keywords daily for Free
Advanced Rank Checker lets you check your ranking on the keywords you provide to the system. You can check your keywords ranking once a day.
This plugin will track your Google Search Engine ranking for keywords which bring visitors to your website.
Google Rank Checker - SEO Tool with Google API provides the estimated Google position for a keyword and corresponding URL.
The Whoosh Traffic plugin provides a Rank Tracker and a Keyword Research plugin integrated right into your blog.