ChargeSmart LLC today launched a Web site that enables consumers to use credit cards to pay mortgages and other bills for a fee and a percentage of the transaction amount. Users of the Web site also can use cards to pay auto and student loans and utility bills, Mitch Friedman, a co-founder of the company, tells CardLine. Friedman says most consumers cannot use credit cards to pay mortgages, so his company is trying to meet that need. Consumers only can pay bills from the 4,000 billers on the site, but ChargeSmart plans to add more, he says. Based in San Francisco, ChargeSmart charges consumers $4.95 plus 2.29% of the transaction amount per payment, Friedman says.