This is a great blessing to anyone who wants lots of keyword combinations http://www.latshawsystems.com/ProductDetails_KeywordExpander.aspx Google limits ad groups to 2,000 keywords and limits your account to around 50,000 total. Most people don't even begin to approach this, but if you want to lower your CPC by increasing the possibility of hitting exact matches that your competitors aren't, you have no reason not to.
why pay for something that is already free on the web? Follow the link on my sig for exactly the same tool BUT free.