Q: Is it worth it ? Powerbook G-4 upgrade to new IOS 6 possible?

Hi my name is Mitch, I have a power book G-4 model powerbook 5,6 which i have had for quite a while and my question is; the laptop is running OSX 10.4.11 would it be possible and cost effective to update my system to run IOS 6  so i can link my laptop with my i phone 4s, I've tried to sync them together but my laptop finds my phone but says it can't open  or link even with the cable atached to the USB port, with this economy I just wanted to know 1) is my system to old and outdated to be updated and would it cost to much to get the new OS, or should i start looking for a newer laptop. This laptop was my first mac and we've been through alot together don't want to lose it