Kudos to the Google Webmaster Central Blog for what seems like a conscious effort to try to address head-on the concerns of the community over common problem areas like duplicate content and 404s. But their most recent effort, which examines the pros and cons of statics vs. dynamic URLs from Google’s point of view, seem to have resulted in more heat than light, with a number of confused commenters responding to the post.
The gist of the entry was that you should probably leave your dynamic URLs as-is, because Google has no problem crawling them; re-writing them, if done improperly, can increase the difficulty of crawling your site, and is also hard to maintain.
I think Google seems to think that doing URL rewrites is more difficult than it is. I would like to think that most websites are either using a CMS that can adequately handle this (as is the case with WordPress, Drupal and Joomla! for instance), or are being run by someone who has the technical expertise to ensure that this is done appropriately and straightforwardly.
There are many reasons for using “cool URIs”, including the fact that they are easier to type, recognize and remember for people. One of the best reasons offered in this article, though, is that if you have a bunch of technology-dependent cruft in your URL, then you decide to switch the underlying technology, you’re going to end up with an entirely different URL structure, thus breaking all the bookmarks and links that have ever been made to your site.
I think the advantages of cool URIs outweigh the risks associated with mapping your dynamic URLs to static URLs, and it is kind of narrow-minded for Google to look at this only as a search engine crawling problem, rather than seeing it in a larger context.
There’s a good post over at SEOmoz on the same topic that lists a bunch of other reasons why, on balance, rewriting your dynamic URLs is still a good idea.