From today's Wall Street Journal Personal Finance Section, Visa will no longer require pin numbers on small debit card purchases. While it may save some time at the checkout, I would not trade that off for the increased risk of fraud. Remember the Sweetbay incidents? Most of those affected were using debit cards. Credit with signature is generally more secure, and you won't incure fees if you pay off your balance monthly. The only ones paying a slightly higher fee for this security are the merchants.
http://online.wsj.com/article/SB1214...1581_middlebox