Need a loan? Log on to PrimeStreet, a Web site that exists to marry businesses with such big-name lenders as Bank One and Mellon Bank. How does it work? You submit an online credit application, then the banks offer terms-effectively making PrimeStreet into a loan auction. Don't' expect bad credit histories to be overlooked (Experian, the credit history company, is a PrimeStreet strategic partner), to put your financing needs in front of name-brand institutions looking to lend to entrepreneurs.