@Jarrod1937May 09.2010 — #Yes, it can make a difference, both for seo and click through rates. Google will highlight the keywords that match a persons query if its in the page title, meta description snippet, and then also if the keyword is in the url. Along with this, having keywords in the url does in fact also provide a minor seo boost.
However, to avoid cluttering up the url with useless words, which only make the url longer and more unwieldy for your users, you'll want to filter out any stop words, as they don't contribute to ranking anyway.