BlackBerry's Mobile Data Service (MDS) enables BlackBerry devices to establish secure HTTP network connections through the corporate firewall, using the BlackBerry infrastructure. This enables devices to easily communicate with corporate web servers and takes care of connectivity and security (read Understanding MDS). I've been messing around with MDS(Mobile Data Service), and although I've only scraped the tip of the iceberg, it is ridiculously simple to create a so-called browser-push application which is installed as an icon on the user's device. The BlackBerry Developer Journal has a sample in PHP which is good enough to start with, and there is a very neat Perl program to do a similar job in BlackBerry Hacks (hack #90). The guys and gals of RIM really thought up some ultra-cool features for their product. It is difficult to impress me; they continue to do so!