In addition to Google Site verification I also noticed today that Google sitemaps is now accepting formats other than their sitemaps protocol schema.
Google sitemaps now accepts RSS 2.0 and Atom 0.3 feeds. They do recommend that you configure your feed to show all articles, not just the most recent ones.
They also accept a text file with one url per line. This is the same format that Yahoo is using for their new sitemaps feature.
And finally they also accept sitemaps in the OAI-PMH (Open Archives Initiative Protocol for Metadata Harvesting) format. I'm not too familiar with this format yet.