Jack Dorsey founder of mobile payments company, Square (and a Twitter founder to boot), tweeted that they are now seeing $3 million per day in payment transactions. Square is chip and pin type device that attaches to a smartphone and allows merchants to turn it into a pdq machine. It took the first 10 months to get to $1m per day, but just three months later, they have tripled that. Spured on by investment from Visa, it certainly looks like Square’s mobile payments are gaining momentum. Many industry observers believe that 2011 will be THE year of mobile payments, and both mobile PDQ and contactless are showing the possibilities.