Have you ever needed a Forward Delete key as well as a normal Delete key? Extended keyboards include such a key, and you can get the same behavior from your iBook or PowerBook keyboard.
While PowerBook and iBook computers do not have a unique Forward Delete key, you can delete the character to the right of your cursor by pressing fn-Delete (function-Delete).
Computers with a fn (function) key include the PowerBook G3 Series, PowerBook (FireWire), all PowerBook G4 models and all iBook models.