US Dollars or travellers cheques.

[betterman]

which do you think is best, i will need some change for the tolls too.

[dzug]

Not a lot of difference. Cash is a lot more convenientand flexible, but TCs are replaceable if lost/stolen. Pricewise virtually identical.

Change is a problem - you'll probably have to resort to buying something at the airport.

[BertiWooster]

You can use dollar travellers cheques like cash i.e without having to change them ; at most places in the resort areas
( assuming that's where you are going )

[spudqueen]

Take mostly travellers cheques (in US Dollars), but some cash. If you've never been before and don't have any change then just change a note at the first toll booth, you have to look carefully for the booths with change.