As Bruno Rocha points, a sitemap is very, very importan for SEO. And other frameworks are adding tools for generating those sitemaps, for example, Django.
"""" The sitemap framework¶ Django comes with a high-level sitemap-generating framework that makes creating sitemap XML files easy. """" extracted from the link http://docs.djangoproject.com/en/dev/ref/contrib/sitemaps/ IMHO, web2py needs for a similar tools, for generating sitemaps. Thanks.

