With the Smart Summary Webpart it is possible to merge data across the site collection. For Example you can display all tasks, checked-out documents and appointments in a SharePoint Platform on a dashboard site, which is really time saving for the user.
Any kind of data can be aggregated into a single view, with the Smart Summary WebPart. In our example, we aggregate the events of all site collections, which could be interesting for the user.
The Fields to be displayed can be configured in the Webpart settings. Of course filtering and sorting of the results is possible via the header.
The user can control the data aggregation via the settings page of the Webpart.