As mac os 10.6 (snow leopard) release last 28th august, all the mac lovers are busy to upgrade. i am already using it . 
Soon i will share my experience.
One of the main feature of this release is the 64bit kernel.Using the following command you can check if your hardware support 64 bit kernel.
$ ioreg -l -p IODeviceTree | grep firmware-abi
Though your hardware is capable to run 64 bit kernel it don’t boot in 64 bit. In this post i will show you how to boot in 64:
1. press 6 and 4 at the boot time. (keep press the 6 and 4 key till you see the apple logo)
2. open terminal and give this command :
$ sudo defaults write /Library/Preferences/SystemConfiguration/com.apple.Boot ‘Kernel Flags’ ‘arch=x86_64′
3. open terminal and give this command :
$ sudo nvram boot-args=”arch=x86_64″
All these way will work. First one will boot 64 bit for just this time. Next 2 are permanent solution.
