Apple Inc. has launched the latest update to its Mac Operating System (OS), offering users a wealth of patches and tweaks — most notably, enhanced security features and improved mobile synching.

The mobile synching improvements promise to get Apple’s MobileMe service out of its shell, following a longer-then-planned gestation period. Originally set for release a couple of months ago, the service has been plagued by technical glitches.

The (US)$99 per year service is designed to transfer updates made to calendars (or contact information from Web sites) from mobile devices such as iPhones to a user’s home-base Mac within a minute of pressing the ‘Send’ button.

The Mac OS 10.5.6 Combo Update is recommended for all Mac users running OS X Leopard. Get it here.