We have developed NetPay, a micro-payment protocol characterized by off-line processing, customer anonymity and relatively high performance and security using one-way hashing functions for encryption. In our NetPay prototypes we have identified three kinds of electronic wallets to store e-coins – a server-side wallet, client-side wallet application, and cookie-based wallet cache. We describe the motivation for NetPay and describe the three kinds of e-wallets and their design. We report on prototype implementations of these wallets and end-user perceptions of their use.