How do I use (n)curses in Ruby?
You might be able to get some implementation ideas from the Ruby/ProgressBar library, which generates text progress bars. I stumbled across it a couple of months back but haven't made any use of it.
Personally I think curses is overkill in this case. While the curses lib is nice (and I frequently use it myself) it's a PITA to relearn every time I haven't needed it for 12 months which has to be the sign of a bad interface design.
If for some reason you can't get on with the progress bar lib Joey suggested roll your own and release it under a pretty free licence for instant kudos :)