There is a utility designed for use with xterm(1), the standard X-Windows terminal program, called xtermcontrol. It's source can be downloaded from the developer's website , and it may also be available as a Fink package. On my 10.3.8 system, it compiled and ran out of the box.
Anyway, it turns out that since Terminal.app implements a subset of the standard xterm/ANSI escape sequences, many of the functions of xtermcontrol will work inside a Terminal window (of course, they all work inside an xterm window). I tried it with iTerm, and it doesn't work well; I haven't tried other terminal-style programs. xtermcontrol checks the TERM variable and will complain if it doesn't find xterm in it. In my Terminal windows, I always set TERM=xterm-color anyway.
For example, you can set the window title with:
xtermcontrol --title="My Window Title"
Or set the window size and location with:
xtermcontrol --geometry=80x25+200+400
You can also find out the current size and so on. You can find out all of the commands using the --help flag. The color and font commands don't seem to work, but many of the others do. You just have to use trial and error. A visually interesting command line to try is:
say goodbye ; xtermcontrol --iconify ; sleep 5 ; xtermcontrol \
--de-iconify; say hello
If you were sufficiently interested, and had too much time on your hands, you could choreograph a whole "Terminal ballet" with xtermcontrol and sleep (with xterm, you also can change the colors "on the fly").
Mac OS X Hints
http://hints.macworld.com/article.php?story=20050223142229375