Great post on how to do this is here:

http://forums.technet.microsoft.com/en-US/sharepointgeneral/thread/21768...

Except for the fact that it puts an emoticon in the tags. Here it is without those:

<asp:Content contentplaceholderid="PlaceHolderMain" runat="server">

add this line

<Sharepoint:SPSecurityTrimmedControl runat="server" PermissionsString="ManagePermissions">

then directly before that sections closing tag (it happens to be the last line in the file) which looks like this

</asp:Content>

add in the closing tag for the SPSecurityTrimmedControl i.e.

</Sharepoint:SPSecurityTrimmedControl>