Using UK debit card in US ATM

I am going to the states this Friday and want to use my UK debit card at an ATM in the US to make one cash withdrawal.  I understand that there will be a conversion rate of 2.75% of however much I take out.  Has anyone experienced this and how bad is that percentage they take out on the conversion? 

It's bad but not much you can do about it - I think you are referring to the fee they charge you for converting the amount from sterling into dollars?  Generally the card companies will charge you a 'transaction fee' or 'conversion fee' to take money out from overseas ATMs.  The actual translation rate you will get should be relatively decent - the bank's rate.  You can't do much better than that legally.  So you have to suck it up and pay the damn transaction fee...

I have yet to find a good card without the overseas fee.  There has been some discussion about it around here somewhere.