For a real quick and dirty method of building a keyword list, I just use Google's handy auto suggest.
As you know, Google.com helpfully tries to guess what you're searching for as you type, even going as far as telling you how many results there are for that phrase. So toss one of the more general [...] type="text/javascript">SHARETHIS.addEntry({ title: "Use Google auto suggest for quick keyword list building", url: "http://www.daynw.com/use-google-auto-suggest-for-quick-keyword-list-building/" });>