No
Surcharging for using a CC card is illegal in the following states: California, Colorado, Connecticut, Florida, Kansas, Maine, Massachusetts, New York, Oklahoma and Texas.
You can however offer a discount for cash in those states - except in New York where no cash discounts are allowed
New fed laws went into effect in Jan, 2013 allowing surcharges providing the retailer
make customers aware up front that there is a surcharge and how much for using a CC - at the store entrance and at the cash register or if an online store at the first reference to accepting CC for sales
You can not use a surcharge for debit cards or prepaid cards (so personally I do not see how you could do this surcharge thing with online payments anyway)
surcharge fees must be itemized on the receipt, in store or online
an overview
http://www.cardfellow.com/charging-customers-a-credit-card-convenience-fee-at-check-out/
