Mobile credit processing start-up Square picked up a high-profile endorsement today–from Barack Obama.

The president's re-election campaign will use the San Francisco-based company's square attachment to process credit card donations.

"Whether you’re a Republican or a Democrat, running for president or local assembly, Square makes it easier than ever for candidates, organizations and volunteers to fundraise for their cause," Aaron Zamost of Square said in a statement.

Square allows anyone to accept credit cards via a small square-shaped attachment to any iOS or Android-powered mobile device.

Square takes 2.75 percent of each transaction but there is installation or monthly fees. The company has about $168 million in funding and processed $2 billion worth of transactions last year.

Most of its transactions were from small businesses and individual users. The Obama campaign raised $42 million in the fourth quarter of 2011 alone.

According to Politico, headquarters staff and volunteers are being issued the mobile credit card readers (they're free, unless you pay $10 for a designer Vivienne Tam version).

In July, Obama participated in a Twitter town hall moderated by Square founder (and Twitter co-founder) Jack Dorsey. (Last April, the president joined Mark Zuckerberg for a Facebook town hall.)

Dorsey appears to be a fan of the president. In December 2008 Dorsey tweeted, "Obama is the only president in my lifetime who's used the word 'empathy.' That's exciting."