Wendong’s Smart Phone Weblog

Similiar to push registry in MIDP 2.0, BREW has a so-called "application-directed SMS".

The interaction of SMS and mobile apps can be used in but not limited to games, information services, and productivity applications:

"- The enabling of games that require a server-generated activity that result in the user taking action (e.g., instant messaging application)
- The delivery of alerts that "wake up" the application and display graphics and text (e.g., news alerts)
- The automatic synchronization of an application with a back-end database when there is an event change (e.g., calendar application)
- The initiation of an activity by the end user opening the application (e.g., inviting another player to a chess game)"

By Radu Braniste:
BREW & J2ME: Let’s Be Friends! (December 4, 2003)
Brew & J2ME: Let’s Be Friends! Part 2 (January 21, 2004)

How many smart phone platforms are there? Symbian OS, Embedded Linux, Windows Mobile, BREW, Palm OS and many other proprietory operating systems. JVM is available for almost all of them, either already built-in or as a third party product.
BREW: Insignia, Esmertec, IBM
Windows Smartphone: Insignia