Online brokerages are positioned to be among the first sectors to use the wireless devices to retain customers, according to a new study by Internet research firm IDC. Investors will continue to do most of their trading and banking on PCs with wireless devices, such as Web-enabled phones and the Palm VII, which should augment the PC, providing a new convenience and improve customer relationships. The study showed that offering wireless services is "unlikely to attract new revenues or generate additional revenues," IDC said Friday in a written statement.