Pardot has just released an add-in for Outlook 2013 (PC only). The add-in allows you to send tracked emails to prospects without leaving Outlook. Simply click the Send with PD button and any links in your email will automatically be tracked behind the scenes. This will provide valuable insight into any prospect clicks and subsequent activity that occur as a result of your message.
See full details and download the add-in at our Outlook 2013 knowledge base article for full details.
Unfortunately Outlook for Mac does not seem to support add-ins so we are unable to offer one on OS X at this time. If you use a Mac, we suggest using our plugins for Apple Mail, Gmail (Chrome), or Thunderbird.