You can see what is being typed into a TDBGrid by looking at the TInPlaceEdit control of the TDBGrid. Care should be taken to make sure that the TInPlaceEdit control is created before trying to use it. The following function will show the data in the column of the grid that is being edited:

procedure TForm .DBGrid KeyUp(Sender: TObject; 
     var Key: Word; Shift: TShiftState);
var
  B: byte;
begin
  for B := 0 to DBGrid .ControlCount -   do
  if DBGrid .Controls[B] is TInPlaceEdit then
  begin
    with DBGrid .Controls[B] as TInPlaceEdit do
    begin
      Label .Caption := 'Text = ' + Text;
    end;
  end;
end;
Please reference TInPlaceEdit in the Delphi 3 help file for more information on it's functionality.