Google announced the release of their own open source XML sitemap generator tool. There are several third-party sitemap tools around that do a great job, but Google decided that they could add some value with their own tool.
As they describe it:
Unlike many other third party Sitemap generation tools, Google Sitemap Generator takes a different approach: it will monitor your web server traffic, and detect updates to your website automatically.
Sounds like an interesting, different approach to sitemap creation. I haven't tried it out yet, but I will try it and report back on the results.
If anyone else has tried it out, post in the comments and let me know what you think about it.