Cell<String> cell = new AbstractCell<String>()
    {

        @Override
        public void render( com.google.gwt.cell.client.Cell.Context context, String value, SafeHtmlBuilder sb )
        {
            FlowPanel fp = new FlowPanel();
            TextBox tb = new TextBox();
            tb.setText( value );
            fp.add( tb );
            sb.appendEscaped( fp.getElement().getString() );
        }
    };
    // Address.
    Column<ContactInfo, String> addressColumn = new Column<ContactInfo, String>( cell )
    {
        @Override
        public String getValue( ContactInfo object )
        {
            return object.getAddress();
        }
    };

<div><input class="gwt-TextBox" type="text"></div>

sb.appendEscaped( fp.getElement().getString() );

sb.appendHtmlConstant( fp.getElement().getInnerHTML() );

sb.appendHtmlConstant("<input class="gwt-TextBox" type="text" value="" + myValue + ""></input>");