There is a new feature in SharePoint 2010 called "Organization browse". In big company, it's quite useful, that it can help user to find the basic relationship among specific users. This relationship is defined by the "Manager" field in User Profile.
Recently got an interesting issue. After updating the "Manager" of one user profile, it seems the change won't take effect immediately. We have to wait for around 20 to 40 minutes, and then, all of sudden, it begin to display the current manager! At first I thought we just need to run a job manually from central administration to refresh the data. But after trying all possible jobs, it still displays the previous manager.
Since the "Organization Manager" is actually a silverlight component, and the data is same to all users, and is read-only, I think it is possible stored in IIS application cache. The test confirmed my guess: after rebooting IIS, the "My Organization Chart" get updated to the current manager.