Caching is absolutely the most effective way to speed up the performance of an app.  However, .NET does not have a reasonable tool for caching data, such as the contents of a database table, across all servers for all users.*  There are third party tools that do this, but they are pricey.

A tool called AppFabric is available from Microsoft (for free) that spans the cache for all users across all web servers in a farm/garden/cluster.  Downside: it’s only available for current operating systems like Windows 7, Vista, and Server 2008.

If you’re interested, here are some tutorials:

http://msdn.microsoft.com/en-us/library/ee677288.aspx
http://msdn.microsoft.com/en-us/library/hh334305.aspx
http://www.microsoft.com/download/en/details.aspx?id=27115

.NET can cache data for all users on one server (using Cache), or for one user on all servers (using Session), but not for all users on all servers