If you need something to do in between of going to Islands of Adventure and Universal Studios Florida, I would definitely recommend seeing a taping of Family Feud at the Universal Studios Florida. It's fun to see, and its free. You don't have to be a park guest to participate.
Here's a article about it: Universal Orlando: Steve Harvey enjoys new gig as 'Family Feud' host in Orlando - OrlandoSentinel.com
Another article with more specific info: Getting a feel for Universal's 'Family Feud' - OrlandoSentinel.com
Note: You may want to watch the tapings when you aren't visiting the park, as it is a time commitment of being part of the audience for two shows, no bathroom breaks.
Family Feud Show at Universal Studios Florida
I have to admit, its nice to see that Universal actually has production at its Florida studios. Disney, of course, doesn't have it anymore