MongoLab is a fully-managed cloud database service featuring highly-available MongoDB databases, automated backups, web-based tools, 24/7 monitoring, and expert support. By hosting MongoDB on MongoLab’s Database-as-a-Service (DBaaS) platform, developers and IT professionals are free to focus their attention on product development instead of operations.
Sign up via the Windows Azure Store directly from the Windows Azure management console by clicking on the MongoLab Icon.
MongoLab Tutorials at windowsazure.com:
Create a C# ASP.NET Application on Windows Azure with MongoDB using the MongoLab Add-On
Create a Node.js Application on Windows Azure with MongoDB using the MongoLab Add-On