From the register:
"Performance is let down, however, by the system bus speed which is limited to 66MHz. Desktop Macs and the PowerBook G4 have a bus speed of 100MHz, and the performance difference is evident in tests. Although fast, the iBook is slower than a similarly rated iMac, and the PowerBook G4 easily outperforms it ? but then as it costs �1000 more you would expect it to. Nevertheless, the iBook is fast enough for most tasks and applications you care to throw at it. Our only other complaint with regard to system specification is the amount of supplied RAM. Of the four iBook models available one ships with only 64MB, while the other three are stocked with 128MB. Given that Mac OS X - Apple's next-generation operating system - which is to be preinstalled on all new Macs, needs a minimum of 128MB to run, this is very poor. "
Amen brothers! Let us pour on the RAM! It is cheap, and cometh from the heavens to speedeth our computing needs!