The powerful command-line 'screen' utility (see this hint for help installing screen) can handle multiple "windows" within the same screen session. It's quite like tabbed browsing in Mozilla or the way kterm works in KDE.
To create a new window you press "Ctrl-A c". To cycle forward through the list of windows use "Ctrl-A n"; backward is "Ctrl-A p", and "Ctrl-D" to terminate the screen. Assuming you have 'screen' installed, here's a quick example:
% screen topOr something along those lines. You don't need tabbed terminal apps after all. =)
[Ctrl-A c]
% screen man tcsh
[Ctrl-A c]
% man screen
[Ctrl-A n] [Ctrl-A p] [Ctrl-A n] etc
[Ctrl-A n] until 'top' is onscreen
q [Ctrl-D]
[Ctrl-D] etc...
Mac OS X Hints
http://hints.macworld.com/article.php?story=20020419094520817