Outlook and Sharepoint works hand and hand to offer lots of nice features. Some of the features which might be helpful in business processes are email enabled lists, using Sharepoint from within Outlook and offline access. There are few products on these features as well.
Check the following links:
- Using Sharepoint with your Outlook Client
- Outlook as a SharePoint client, online and offline
- Incoming Email in SharePoint v3
- How to access SharePoint sites through Microsoft Outlook
- Configure Emailed Enabled Sharepoint Lists with Exchange