Josh Gavant is a Senior PFE in the Central US PFE team. has recently shared some awesome details on how SharePoint uses Windows Server AppFabric caching services to achieve better performance and scalability.
In Part 1 of the series Josh starts by explaining the different types of cache used by SharePoint, zooming in on LogonToken and ViewState caches.
In Part 2 he then goes in-depth into the AppFabric physical architecture and details the Cache Host configuration, including how the cache eviction and expiration is controlled. He wraps up his series with some guidelines on sizing and providing for high availability.
These posts are extremely good reads – do set aside some time to read them in-depth, and do send your comments to Josh!