<asp:DataList runat="server" id="myDataList">
  <ItemTemplate>
    <b><%# DataBinder.Eval(Container.DataItem, "Column from DataSource1") %></b>
    <br />
    <%# DataBinder.Eval(Container.DataItem, "Column from DataSource2") %>
  </ItemTemplate>
</asp:DataList>

DataTable customTable = new DataTable();
        customTable.Columns.Add("Column1");
        customTable.Columns.Add("Column2");

        DataRow drNew = null;
        foreach(DataRow dR in 1stDataSource)
        {
            foreach(DataRow dR1 in 2ndDataSource)
            {
                if(dR["ID"] == dR1["ID"])
                {
                    drNew = customTable.NewRow();
                    drNew["Column1"] = dR["Column1"];
                    drNew["Column2"] = dR1["Column2"];
                    customTable.Rows.Add(drNew);
                    break;
                }
            }
        }

        myDataList.DataSource = customTable;
        myDataList.DataBind();