[angvelem]

Ищи по тематике "иконка в трее".
Может это поможет:

Код:

function TaskBarAddIcon(hWindow: THandle; ID: Cardinal; ICON: hIcon;
			CallbackMessage: Cardinal; Tip: PChar): Boolean;
var
  NID: TNotifyIconData;
begin
  FillChar(NID, SizeOf(TNotifyIconData), 0);
  with NID do
  begin
    cbSize := SizeOf(TNotifyIconData);
    Wnd    := hWindow;
    uID    := ID;
    uFlags := NIF_MESSAGE or NIF_ICON or NIF_TIP;
    uCallbackMessage := CallbackMessage;
    hIcon  := Icon;
    lstrcpyn(szTip, Tip, SizeOf(szTip));
  end;
  Result := Shell_NotifyIcon(NIM_ADD, @NID);
end;

function TaskBarModifyIcon(hWindow: THandle; ID: Cardinal; Flags: Cardinal;
			  ICON: hIcon; Tip: PChar): Boolean;
var
  NID: TNotifyIconData;
begin
  FillChar(NID, SizeOf(TNotifyIconData), 0);
  with NID do
  begin
    cbSize := SizeOf(TNotifyIconData);
    Wnd    := hWindow;
    uID    := ID;
    uFlags := Flags;
    hIcon  := Icon;
    lstrcpyn(szTip, Tip, SizeOf(szTip));
  end;
  Result := Shell_NotifyIcon(NIM_MODIFY, @NID);
end;

function TaskBarDeleteIcon(hWindow: THandle; ID: Integer): Boolean;
var
  NID: TNotifyIconData;
begin
  FillChar(NID, SizeOf(TNotifyIconData), 0);
  with NID do
  begin
    cbSize := SizeOf(TNotifyIconData);
    Wnd    := hWindow;
    uID    := ID;
  end;
  Result := Shell_NotifyIcon(NIM_DELETE, @NID);
end;

на контексте такой иконки можно выводить текущее время.