we are trying to customize the look and feel in SP07 by adding a logo
image to the top bar where the link to home is currently present. I
was able to display to image properly but was unable to make it a
hyperlink (to the homepage) like the earlier text used to be. How do I
do that?

here is my code from the default.master-

<asp:ContentPlaceHolder id="PlaceHolderGlobalNavigationSiteMap"
runat="server">
<asp:SiteMapPath SiteMapProvider="SPSiteMapProvider"
id="GlobalNavigationSiteMap" RenderCurrentNodeAsLink="true"
SkipLinkText="" NodeStyle-CssClass="ms-sitemapdirectional" runat="server">
<CURRENTNODETEMPLATE>
<asp:Image id="Image1" runat="server"
ImageUrl="/_layouts/images/WhiteRed.jpg" AlternateText="Our Portal"/>
</CURRENTNODETEMPLATE>
</asp:SiteMapPath>
</asp:ContentPlaceHolder>