Microsoft just released it's CTP-1 of a new caching product code named Velocity. It is a distributed caching technology that should add extra velocity to your ASP.NET applications.
Summary: “Velocity” is a distributed in-memory application cache platform for developing scalable, available, and high-performance applications. “Velocity” fuses memory across multiple computers to give a single unified cache view to applications. Applications can store any serializable CLR object without worrying about where the object gets stored. Scalability can be achieved by simply adding more computers on demand. “Velocity” also allows for copies of data to be stored across the cluster, thus protecting data against failures. “Velocity” can be configured to run as a service accessed over the network or can be run embedded with the distributed application. “Velocity” includes an ASP.NET session provider object that enables ASP.NET session objects to be stored in the distributed cache without having to write to databases. This increases the performance and scalability of ASP.NET applications (17 printed pages)
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Cross posted from my blog at http://schema.sol3.net/kbarrows