Use a third-party CSS or JS Framework, a self-hosted service like a CRM, or a third-party service with the site.
This module integrates the excellent open source WebCalendar (http://webcalendar.sourceforge.net) php calendar script into Drupal.
The WoWRoster Integration displays WoWRoster inside Drupal.
Amberjack (http://amberjack.org/) is a lightweight Open Source library, enabling webmasters to create cool site tours.
The MicroID Module - Dynamicly generates a MicroID hash from a node authors email and the URL of the node.
This module enables you to use Technorati tags in your content.