Abstract: A mobile, handheld electronic (processor-based) device that can be used for banking functions, including writing checks from a checking account, confirming the account balance, reviewing account activity in a ledger format, and other banking-related functions. Using the processor, the device may: (a) maintain and display both a ledger for the personal bank checking account and a current account dollar balance for the personal bank checking account based on the check data and the deposit data stored in the at least one memory; (b) transmit, via a local data network, data for a new check written by the user from the personal bank checking account at a point-of-sale location; and (c) update activity for the checking account with transaction data received from a remote bank computer server system via the mobile telecommunications network.