Hello everybody, Maybe you remember me from some other topics. OK, I decided to buy an iBook 12" when I visit Miami in December, and I want to know if buying extra 256 MB SDRAM is really necessary. Knowing that's a "build-to-order" option, which costs more $75, I want to know if it really makes difference at the performance of the computer. Another doubt is: how many gigabytes Mac OS 10.4 occupies in the hard disk? PS.: I will use this Mac to make school works, access the Internet, communicate with my friends, listen to music, use Photoshop and get my photos from a digital camera. Thanks!