Web Parts in Microsoft Office SharePoint Server 2007 can be targeted to appear only to people who are members of a particular group or audience.
An audience can be identified by using a SharePoint group, a distribution list, a security group, or a global audience.
On the Web page that contains the Web Part, on the Site Actions menu, click Edit Page.
On the Web Part, click the Web Part menu , and then click Modify Shared Web Part.
Under Advanced, enter one or more audience names in the Target Audiences box.
When the page is rendered, the Web Part appears only to the people who are members of the audiences that you specified.