Do you have a heartening/ tearjerking/ heroic nursing story-- one where we all say "Yeah. THAT's why I went into nursing" Start with a couple of those scenarios. Or, tell how the school nurse in Queens was instrumental in identifying the link to H1N1.
Emphasize how there are so many things you can do in nursing-- from schools to ER to OB to flight nursing to travel nursing to armed services etc etc etc.
(My presentation is to kindergarteners, so my audience is a little easier!!)