i was wondering if i should exchange pounds to us dollars before i get there???

Or should i just use my gbp visa card??

I have heard it is best to buy us currency rather than use the visa card?

When I travel to Europe, I take enough local currency to get from the airport to my hotel. Then I use the ATM cash machines. It's convenient, I get a good rate, and I don't have to pay an exchange fee.

You will get a better rate with your Visa card and by taking US dollars out of ATMs than with any currency exchange service. Pay for purchases with Visa - that's the best rate. Use ATMs for cash - the second best rate. Bring maybe US$50 with you for your first few hours, converted at home - a worse rate.

i am from holland and i am going to NYC in october..
i have already exchanged euro's for dollars,, total of a couple hundred dollars.. because if you get there and you have bad luck with the atm or maybe with your card, then at least you will have enough money for the first night hotel and something to eat..... always be prepared is my motto