SharePoint 2007: Update global links Like My Links

Open C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\TEMPLATE\CONTROLTEMPLATES\MyLinks.ascx

Add a line
<td class="ms-globallinks"><a href="http://www.google.com">google</a></td>

under line
<td class="ms-globallinks"><asp:Literal id="hlMySiteSpacer" runat="server" /></td>