Recently, Google's Matt Cutts has given a very nice presentation at WordCamp San Francisco 2009 that was held on May 30. The presentation was not only a useful one, but at the same time it was exciting and fun to watch! Here is the video of Matt Cutts' presentation:
In the presentation, Cutts said that there is nothing wrong in putting keywords in URLs. In fact, if you want to rank better for alternatives to the title of your page, then it is necessary to put the keyword in the URL.
Slides from the presentation can also be found on Google Docs.
Forum discussion is going on at DigitalPoint Forums.