Battery Park, New York City
Amidst the touristy stalls were groups of people peddling some very dodgy looking goods, clearly illegal and could get quite intimidating if entered into a conversation with. Avoid eye contact and be on your way.
If you want to Visit Ellis Island and the Statue of Liberty, you'll have to take the ferry from Battery Park. Do no buy T-shirts there. Its bloody expensive. You get the same at one-sixth the price. I was waiting in line to catch the ferry and thought I'd buy some tourist (cheap) T-shirts for friends back home. The vendor charged me US$ 5 per piece (which I, of course, thought was expensive but then thinking that NYC being an expensive city, thought that it was OK). Later that day, I saw the same T-shirt around Times Square where, after some bargaining, I bought 6 pieces for US$5.
Don't fall for the trap
Unique Suggestions: If in NYC as a tourist, you'd want to buy some memorallas to take home. With due respect to the vendors there, try not to shop there. Buy one basic stuff if you want one and do the bulk of the shopping at some larger market area where there is some sort of competition for these vendors.
Don't let the taxi driver's decide your tipping! We are used to that tips shall be given as a sign of sacrifice with the service a person has offered you, in NYC it is different, there the tips is the payment for the people in the service business. We knew tips would have to be included at all services we bought, and we were prepared to pay between 10-15 % of the total amount in tips.
The taxi drivers ,in special, turned out to be more rude when it came to the tipping than we had expected. Our first experience was from the airport to our hotel at Manhattan, a tour that originally was quite expensive ($60), and I would believe atleast $10 of those dollars went the to driver himself, which is an O.K payment for 30 minuttes of work. But this driver made it quite clear that he expected 15% tips, non less.
The second experience was made after a rather short tour from our hotel down to the Battery park. The meter said it would be 7$, we gave him a $20 and told him to give us $12 back. He smiled at us and gave us a $10 and said - 'I keep the rest'.
I would never have accepted such a behavoir from a taxi driver back home! Shame on you, NYC taxi drivers ;)