I got in on the iBook2 when it first came out(~may of 2001), with the sole puprose of running Linux on it. I have been using linux in various forms since just before the 2.0 kernels....so, grain of salt, I am use to having to tinker. I knew that it would be work...and it was. A lot of stuff wasnt supported....I spent a great deal of time pestering the heck out of people like BenH to figure out what was just my fault...and what was really just not supported. All that being said....That was a Year ago. Linux on the iBook2 is really an amazing thing now. I have since rebuilt the whole laptop to Debian(from Yellow Dog) and it couldnt have been easier(grain of salt again. I woouldn't necesarily expect my Mom to do it, but if you have some decent Linux xperience...should be no problem). Addressing some of the comments:
First, this ain't your fathers x86 machine. You better be darn familiar with building a kernel in the first place before you go blindly trying to compile a ppc kernel. Does it mean you shouldn't? No, just follow the how-to's pointed out by the article till you are familiar with your piece of hardware and the ppc kernel.
the iBook2 I bought has bouilt in USB, Firewire, 10/100 ehternet, Airport, VGA out, cdrom, cd-r, cdr-w, dvd, modem(hardware). What else am I gonna need?? Ok, I added a 512mb dimm and a 30gb hd. The ram took about all of 2 minutes...and 90 seconds of that was figuring out how the 3rd hook of the keyboard came loose. The Hard drive...well, that wasn't fun. ok, in fact it was horrible, but only cause I didn't print out one of the 3 million how-to's on the net before hand(and that stupid snap on bottom plate, argh!). Not like a Apple dealer couldnt do it for you for a few bucks.
Ram: I got Ram off the net.....had to wait 6 weeks before it was available. I havent had a problem with it ever....and it ain't Mac OEM ram. Just ram from a decent name dealer(think I found it on www.dealnews.com).
Do I have any complaints? Sure. One. Flash support is pretty much non-existent. thats it. I could complain about the battery life...but it lasts 4-5 hours at a go...and batteries them selves are only about a $100 so having two ins't a hardship. Not much else to say other than....its a great fit. Apple Hardware and Linux.