We were in Aruba in April, 2003. We hired a taxi driver right at the pier to take us on a tour of the island. It was about 2 hours and cost about $20. pp. We wanted to see the Natural Bridge on the other side of the island and several other areas of interest on the island. It was a great tour. There are many taxi's right where you get off the ship, and they will take you where ever you would like to go. Don't know what type of independent tour operators are there. After we got back, we just walked into town, right there, and they have lots of shops and also there is gambling on the island. So we did a litttle gambling and bought a few souvenirs while there. You could also take a bus over to the beach area. They run about every hour and they cost either $1. or $2. pp.
Aruba was our favorite island, and waiting to go back for a week's land vacation hopefully in 2006! Hope this helps some.