Pat, we also prepaid one of the night's stays at the Grand Hyatt last year in Santiago. The final bill was printed out in CLP (Chilean Peso) with US$ equivalent next to it. The tax was NOT included, and I think the essential part of the transaction was using the credit card. If I remember correctly, there's a separate piece of paper you get at immigration and you turn in when you leave. That must be the 'tourist card' mentioned on the website Marc found.
The basis for the visa entry fee (according to the Chileans) is because they have to pay a visa fee to enter the US, Canada and Australia. Fees used to be $100 - US and Chile each raised it to $131 1/1/2008. I didn't check Canada or Australia.
Who else thinks Chile takes in more visa revenue from US, Canadian and Aussie visitors than vice versa?

. That said, it's a great place to visit. Can't wait to go back. Enjoy your pre-cruise stay. Have a great cruise!
Cheers, Anne