Businesses and consumers may well embrace phones as payment devices, said The Yankee Group analyst John Jackson.
"Given the proliferation of cell phones and their computing capabilities, it's a logical extension of what you do today with your debit card," Jackson said.
Java and SIM cards are logical components of such a system because both are so widely used in mobile phones, though they are not used by CDMA (Code Division Multiple Access) subscribers, who make up about half of cell phone users in the U.S., Jackson pointed out. There are more than 600 million Java-enabled handsets in the world, according to Sun.
Two challenges Sun faces in making its vision a reality are achieving consistency across the Java platforms on different phones and establishing a standards-based back-end infrastructure such as the Sun-backed Liberty Alliance, Jackson said.
Also at 3GSM, Sun is set to showcase its Java System Content Delivery Server, a platform for managing, delivering and billing for mobile content such as games, ringtones and screen wallpaper.
At its booth, the company will demonstrate Project Lemonpeel, a prototype of a system for delivering a content lineup tailored to an individual user's preferences, Rivas said. In addition, mobile infrastructure vendor Telefonaktiebolaget LM Ericsson will introduce a new managed content delivery service for mobile operators that is based on the Java System Content Delivery Server, according to Sun.
(Peter Sayer in Paris contributed to this report.)