Turning off current directory display in a terminal window

[Robert Moskowitz]

How might I turn off (or change) the display of the current path in a 
terminal window?

For example I have one terminal window with:

rgm@LX140e-3:~/data/htt/Projects/Critical/drafts/draft-ietf-drip-rid/dki-try2$

That is the whole line is taken up with the current directory!

I would be happy if only the lowest dir level is showing, e.g.:

rgm@LX140e-3:dki-try2$

Or some such.

But not to make a permanent behavior change, as MOST of the time, seeing 
where I am is helpful.

thanks