This site has ATV tours and limo/shuttle services.
De Palm Submarine and other tours
L.G. Smith Blvd. 142, Oranjestad, Aruba, +297 522 4400
This company offers really unique tours including submarine and sailing adventures. Snorkeling and UTV tours are also available. They also do airport transportation.
Aruba Ostrich Farm
Matividiri 57, Paradera, Aruba, (+297) 585-9630
Super cool and affordable opportunity to get up close and personal with some unique creatures.