The Google Keyword Tool has a variety of helpful features meant to streamline the keyword research process. By entering terms or phrases into the search box, the Keyword Tool allows you to build extensive, relevant keyword lists from one simple interface. By default, the tool displays Advertising Competition, Global Monthly Searches, Local Monthly Searches, and Local Search Trends for each keyword. Additional options allow marketers to show the estimated Average Cost per Click, Ad share, and Search Share.
In a nutshell, Long Tail Pro helps you quickly find keywords in bulk based on a seed keyword that you input. In addition to returning hundreds of related keywords, the tool also shows search volume (monthly search volume), advertiser bid, number of words, rank value, and my favorite Keyword Competitiveness (helps you judge the competition and keyword difficulty).