Take a look at the various "10 Hottest Certifications" lists at www.certcities.com, and this article: http://www.certcities.com/editorial/features/story.asp?EditorialsID=76. You will be very safe profiling one or more of these credentials as among the most popular certifications around. If you visit other sites like www.informit.com/certification or www.gocertify.com you'll be able to dredge up all the details necessary to entice career day attendees.
FYI, I've also recently developed a "Planning an IT Career" course for Michigan Virtual University (see www.itcareercenter.org). You may also want to point career day attendees at this excellent resource as well.
This was first published in February 2004