[Aristarh Dark]

Можно именно ProgressBar туда поместить.
Вот пример из drkb:

Код:

var pb: TProgressBar;
{©Drkb v.3(2007): www.drkb.ru}
begin
....
pb:= TProgressBar.Create(self);
with pb do begin
   Parent:= StatusBar1;
   Position:= 30;
   Top:= 2;
   Left:= 0;
   Height:= StatusBar1.Height - Top;
   Width:= StatusBar1.Panels[0].Width - Left;
end;  //with;
pb.Visible:= True;
....
end;