MacBook Pro Software Update 1.2 - 14.4MB
This update improves graphics stability and is recommended for all 2.2/2.4GHz MacBook Pro Models.
iMac Software Update 1.2 (Tiger) - 13.3MB
This update provides important bug fixes and is recommended for 20-inch and 24-inch iMac models with 2.0, 2.4, or 2.8GHz processors.
iMac Software Update 1.3 (Leopard) - 21.6MB
This update provides important bug fixes and is recommended for 20-inch and 24-inch iMac models with 2.0, 2.4, or 2.8GHz processors.
The iMac Updates reportedly do not help iMacs which are freezing. Apple's discussion boards are the best place to follow the ongoings.