Are you talking about Disney World, or one of the other locations? If it's Disney World, there's a lot of different stuff to do in Orlando.
You have to do the Magic Kingdom. After that, it really depends on what you're into.
If you like thrill rides, you need to visit Universal's Islands Of Adventure. They have some of the best thrill rides in the US. And Disney's thrill rides are really pretty tame.
Adults tend to prefer EPCOT for their variety of shops and restaurants. Lots of people spend the daytime at the other parks, and head over to EPCOT in the evening for dinner.
MGM Studios has a few good rides. But most of the attractions are shows. If you're just interested in the rides, you could probably do it in half a day.
Animal Kingdom can be done in half a day, unless you like to linger and see all the animals. There's really only a few rides worth doing. Expedition Everest, the Safari, Dinosaur and Kali River Rapids.
Also consider visiting the two water parks. Blizzard Beach is the newer of the two and has more slides. Typhoon Lagoon has the shark reef and wave pool.
If you friend's looking to do some shopping (since the US dollar is so low), check out the outlet malls. Orlando has some of the biggest outlet malls in the country with everything from The Gap and Old Navy to Versace and Armani.
Check out the
WDW Park Updates at MousePlanet for schedules, attraction closures, discounts and special events.
Also, check out
MouseSavers.com for discounts on hotels, tickets, car rental, restaurants, etc.