Certainly is. You need to insert a textbox from the Control Toolbox (one of
your toolbar options) instead of a textbox from the Drawing Toolbar. If you
want to be able to do something with that text, you will need some
programming skills as VBA can manipulate that text. I have a simple
calculation example on my site at:
http://www.pttinc.com/ppt_faq8.html if
you want to see how to use VBA code.
Maybe if you provide a little more of what you are trying to accomplish, we
can provide more specific solutions.