More Ram for my iBook G3

I've got an iBook G3, running 10.2.8 (tiger coming soon) and my 384 (128 build in, 256 added) MBs of ram just arnt cutting it. I've been looking into getting a 512 or 1 gig stick to put into this thing, but i have no idea what to get.
Umm, its an iBook G3, 800mHZ processor, 40 gig HD, combo drive, and i think thats all i can tell you. I'm pretty sure its a 144 pin ram. And, i do know that the expandable ram goes under the keyboard, under the airport card.
Thanks, and move this if its in the wrong forum