2007 introduces a new feature called Content Types. In general, you have much more granular control over the manner in which information is stored in Document Libraries and Lists. For example, you can have multiple document types associated with a single Document Library, each with an associated document template, workflow process, and metadata. Therefore, you could use the Content Type feature for a central repository of sales contract documents. As the contract goes from in progress, review, approval, and submit states, the associated workflow processes could perform various actions, such as changing the document's permissions once it has been approved, converting the document to PDF, and so on.

Let’s take this same thought process and apply it to Custom Lists now. One scenario that immediately comes to mind is the ability to quickly create a single list for journaling various types of activities. For example, while working with a customer through a sales or project cycle, it's a good idea to journal the various activities. Your journal could contain things such as simple item entries, tasks, events, or virtually any other journal type you deem appropriate. The nice part about this is the ability to see all activities for a customer or project in a single holistic view instead of having to jump around from list to list. Let me walk you through the steps for creating a simple Custom List and adding various Content Type options and see what the results are.

Creating Your Custom Journal List

Go to the site where you want to create the new Journal Custom List. For the sake of this demonstration, I simply created a temporary site and called it Demos/Journal. Once you're on the site, select View All Site Content and click the Create link. This will take you to the screen where you can choose which type of content you want to create.Give the new Custom List a name and description, then press the Create button.

By default, your new Custom List will contain a single column named Title. We'll use this as the common title for all Content Types associated with this Journal List.
Before we can add other Content Types, we need to tell SharePoint this list should support them. By default, a list will support one type of content. To change this setting, click the Settings drop-down menu and select List Settings.

Next you'll be taken to the Customize Journal page, which displays a wealth of settings that let you customize your list. Click the Advanced settings link, located under the General Settings group.
Now you should see the Journal's Advanced Settings page. The first section contains the setting for allowing or disallowing the management of Content Types. By default, this will be set to No; change it to Yes, and click OK to save your changes. You now have the ability to manage different types of content for your Journal List. Let me demonstrate.
Back on the Customize Journal page, you'll now see a new section labeled Content Types. Because you started with a simple Custom List, there's a single Content Type called Item already available. This Item Content Type adds an entry to the Journal List: a single column of data called Title.

For the purposes of this demonstration, let’s add a new Content Type to store a Task. To do this, click Add from existing site content types, which is located below the list of available Content Types.
You'll be taken to the Add Content Types page in SharePoint, giving you the opportunity to add various types of content to the Journal List. In the first drop-down menu, select List Content Types, then select Task and click the Add button.

Click OK. Now return to your Journal list entry screen and select New, Create a new list item. Now you have two Content Types from which to choose.

Take a moment to add one of each item into your new list and see what the outcome is.

There are many types of applications for which you can use the Content Types feature. The ability to use various types of information associated with a list lets you focus on the centralization of that information instead of what list it belongs in.