Type in a keyword phrase into the "Analyze Keyword" box and press "return". The keyword you typed in will appear on the left panel and after a few seconds the right panel will display the top competing domains (in Google, Yahoo and Bing) for that keyword.
The data table includes the various domains along with the ranks in Google, Yahoo and Bing. A relative strength is also displayed (as a bar graph). This is calculated based on the ranks in the three search engines.
Right click within the list for more options. You can copy the data to pasteboard, open the site in your browser (external) or send the domain to the site analyzer.
You can select different data views form the "display sector" in the toolbar or from the "Brainstorm" menu.
The string matching search filter on the top right will help you filter the displayed data. You can use it to quickly find domains that have a hyphen, ".com" domains, keywords that contain a specific word, etc.