Example:
DataSet data = new DataSet();
SPWeb site = SPContext.Current.Site.OpenWeb("/SiteName");
SPList list = site.Lists["Listname"];
data.Tables.Add(list.Items.GetDataTable());

1. Navigate to "~Program Files~\Common Files\Microsoft Shared\web server extensions\12\TEMPLATE\CONTROLTEMPLATES" on your SharePoint 2007 Server
2. Edit the file "VariationsLableMenu.ascx" and uncomment the line <cms:VariationsLabelEcbMenu id ="varlabelmenu1" DataSourceID="LabelMenuDataSource" DisplayText="<%$Resources:cms,VariationLabelMenuTitle%>" IsCallbackMode="true" runat="server" />
3. Add the tag <%@ Register TagPrefix="PublishingVariations" TagName="VariationsLabelMenu" src="~/_controltemplates/VariationsLabelMenu.ascx" %> to the header of your masterpage.
4. Add <PublishingVariations:VariationsLabelMenu id="labelmenu1" runat="server"/> in your masterpage to show the standard VariationsLabelMenu.