One of the Drupal modules that I maintain is the Pathauto Module which automatically creates user-and-search-engine-friendly aliases for your Drupal paths.

So while a normal site might have node/429 as a path, a site that uses Pathauto can easily get that to become aliased as /blog/greg/200706/title-of-post. Pathauto uses a simple token replacement system to achieve this magic.

All this and more details on the module are available in the podcast. Full Podcast page here - I hope you enjoy it!