Should I upgrade to 10.5 or 10.6?

I want to get started developing apps for the iPhone. I have a PowerBook Core Duo 2 Ghz. Now I have 10.4.

It looks like the iPhone SDK requires 10.5 or higher. Give me some advice should I Just go up to 10.5 or should I go for 10.6. Are there any headaches involved with the process?

What machine do you have? Is it a Powerbook or a MacBook? You stated Powerbook - if that's the case....

You don't have a choice since Snow Leopard (10.6.2) will only install on a machine with an Intel processor. Use Leopard (10.5.8).

Regards.

Looks like I have an Intel core 2 duo. I was mistaken, it's not a powerbook, it's MacBookPro 2.2.

Model Name: MacBook Pro 15"
Model Identifier: MacBookPro2,2
Processor Name: Intel Core 2 Duo
Processor Speed: 2.16 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache (per processor): 4 MB
Memory: 2 GB
Bus Speed: 667 MHz
Boot ROM Version: MBP22.00A5.B07
SMC Version: 1.12f5
Serial Number: W865008SXDL
Sudden Motion Sensor:
State: Enabled

OK. That's a much better machine. Go for the Snow Leopard update. You can install it clean - as a matter of fact, that's really the only way you can do it since you can not upgrade directly from Tiger.

Regards.