I would have to say that my favorite computer science class was Computer Science 160: User Interface Design, Prototyping, and Evaluation. The course covered many topics concerning Human-Computer Interaction including human capabilities, interface technology, interface design methods, and interface evaluation. The semester I took the class, everyone was given a PDA. The main assignment for the class was to propose a new interface to solve an everyday problem within the constraints imposed by the PDA. My group chose to do an E-Cash and Finance Manager for the PDA which we dubbed "Pocket Change". I found the old project pages we created still housed on a berkeley server. Much of it was missing off the server, but you can still get a feel for what we built and the process we went through.

• Check Out Pocket Change

  
  Problem

  People currently use many forms of currency - credit cards, checks, and cash; yet each of these systems is somehow insufficient - credit cards can't be used to pay people back directly, checks require a trip to the bank to deposit, and cash is difficult to make exact change with. Aside from a better system of currency, people require an efficient, mobile way to easily keep track of all the different types of money that they spend.

  Solution Overview

  The Pocket Change system incorporates the functionality of electronic cash (e-cash) and a finance manager into a PDA. The e-cash functionality of the system allows the user to make purchases with e-cash and exchange e-cash with other users of the Pocket Change system. Both of these transactions require fingerprint validation to ensure security. The finance manager functionality allows the user to maintain a history of e-cash transactions, as well as a history of other financial transactions that are impo rted from an external system(s) via a web interface. The Pocket Change system is designed to take the place of cash for users from a broad set of backgrounds and is therefore easy to use for someone with little computer experience.