Sharing information between User Controls

I recently helped a friend clean up some code he inherited.
This web application had many user controls which needed to maintain some common information between each other. So each user control loads up the state from the business logic for each of it's instances.
As this was too repetitive and a performance hit, I decided to use per request caching. So only the first instance loads the information, and subsequent request are thought the cache.

More information here:
http://aspnet.4guysfromrolla.com/articles/060904-1.aspx