[iBook] Security

[Michael Max L.Ac]

I recently bought a new iBook, and will be selling an older Powerbook.

>From a security point of view. Should I erase the disk, and then re-install
everything? (that will probably take an afternoon of my time), or are there
recommended utilities that will zero the unused sectors.

Or if I just delete my account, how difficult would it be to recover the
data files if the new owner were really nosy?

Thanks
Max