The latest point update for Mac OS X Leopard has just been released. If you thought OS X 10.5.2 was big, hold onto your socks because 10.5.3 is even bigger. The combo update for versions of Leopard prior to 10.5.2 is 536 megabytes and the standard update for users of 10.5.2 is a still staggering 420 megabytes.

Still, with big sizes come BIG changes, fixes and features. Apple has the full list, but here are some highlights:

• Addresses stuttered audio or video playback from certain USB devices
• Improved Airport and 802.11x behavior and reliability
• iPhone users can now sync their address book contacts with their Google account
• Safari works better when connecting through a Microsoft ISA proxy
• Improved Spotlight search on AFP volumes
• Improved iCal syncing
• Fixes issues with authenticated RSS feeds in Mail.app

Plus improvements to Time Machine, Spaces, iChat, .Mac and Parental Controls. Apple is recommending this update for all users, but as always, encourages making backups of important files and folders before installing.