Windows Azure SQL Database Marketplace
Microsoft Principal Architect Steve Peschka just finished up an interesting three-part series of posts on his Share-n-dipity blog that detail how to build a custom claims provider for SharePoint that uses Windows Azure as the data source.
At the end of this series, Steve says readers should have an end-to-end SharePoint-to-Cloud environment running on Windows Azure. This series includes proof of concept as well as complete source code that you can use as you wish.
To learn more about integrating SharePoint and Windows Azure, be sure to check out the “SharePoint 2010 and Windows Azure Training Course” on MSDN.