i've had a 12" iBook since late last summer. Mine is the 1Ghz G4, i upgraded to 768mbs of mem, and it has bluetooth, airport, superdrive, and the 40gb hd.
So far what I've experienced is random really hot girls walking up to me at coffee shops and commenting on hot cute it is. I've had hardcore PC users won over because while there laptops crash and they need a bag just for the wires i just sit down and plug some headphones in and go.
Your going to have a great experience the iBook G4 is more then adiquate for most photoshop jobs, some gaming, and actually i'd suggest it for everything but movie editing
Its been abused in some horrible ways from poolballs flying off tables and hitting the back of its screen (which caused it to go to sleep but a quick close and open of the lid woke it back up and i went on playing my game with nary a snag), to water leaking in my backpack and soaking it (which it was fine about). Its also been in a car crash where i was rear ended and shoved under a semi in front of me. Every morning it wakes me up with some cheerful music and it takes me through my classes my free time and then back home for some relaxing music, games, or research. Whenever i leave the house without it i need something from sherlock (movie times etc) and wish i had brought it so now it goes everywhere with me!
Really the only thing I could complain about with it is you get PC users who laugh, which then you have to do something like run expose and they keel over in amazement; and the linux crowd who are annoyed because...well just because i haven't figured that one out, maybe it just is to easy??
Basically your going to have a good friend for the next couple years