Yeah, I agree. I think it's much more work than it's worth. RAM is a pretty cheap way of speeding a machine up and if you're still running on the original 4200RPM drive then you'll notice quite an improvement getting a new 7200RPM drive.
Save your money toward a low end Macbook. Old technology is rarely worth the money to upgrade. Spend your money toward a new item and load it up early so you won't have to upgrade later. I generally keep my computers for 4 years before selling them for a really cheap price. Very happy with my Rev. A Dual 1.8. I'll wait another year & half & sell it then for a bit.
how much usage are you going to get out of your investment/upgrade now compared to putting that money toward a more future-proof machine?
I second and third the previous comments: more ram, faster HD. Or just save yourself and get the macbook.
from a 1.07 to a 1.2? You're not going to notice anything like the jump in speed you'd get from just upgrading to a new machine, and you're looking at two costs here.
1: the cost of the upgraded card [which may not be reliable even after you've put it in]
2: your time and energy. I have an ibook that's a pet project, I've opened the case and replaced hardware in it several times. But it is a seriously agonizing project each time. Those machines are not intended to just be taken apart and futzed around with. You're talking several hours of work just to get it in, then several hours to rebuild your comp and test everything to make sure it works. And if you miss a screw or forget to plug in the sleeplight [like I did], you get to start all over.