Yep, the iBook and the iMac G5 have mini-VGA outs that use the same adaptors (Mini-VGA to VGA or Mini-VGA to composite/S-Vid). The Macbook and iMac CD/C2D, as far as I know, both use the same mini-DVI connectors which output Mini-DVI to VGA, DVI (and can be converted to HDMI also), or Composite/S-Vid. So there are a total of three different adaptors that can plug into that port. They're all available from Apple, about $20US each.