If you're using KDE go to the menu, select "Run command" and put in konsole
Likewise with GNOME but put in gnome-terminal
If you don't want to use either of those, there's also xterm or rxvt installed by default.
To get it back on the taskbar, create a launcher to whichever terminal you want, be it konsole, gnome-terminal, xterm, rxvt, or any other. You can also add it back to the menu using menudrake.
Hope that helps