Securely delete files...

[reynt0]

On Thu, 21 Aug 2008, David Shaw wrote:
  . . .
> whether the filesystem you are using overwrites in place or not.  Many modern 
> filesystems (Reiser, XFS) do not necessarily overwrite in place.  More 
> primitive filesystems (like the FAT FS that is used on many external disks) 
> do overwrite in place.  Linux systems most commonly use ext3, and that may or 
> may not overwrite in place, depending on how it is configured.  Then there is 
> the fact that many programs create temp files here and there which wouldn't 
> get shredded.  On top of that there is the fact that many programs save files 
> in ways that can defeat shredding.  Bottom line: it can be safe, but you have
  . . .

Might anyone have any quick info about this issue for MacOS?
From, say, OS10.2's HFS+, through OS10.3 and 10.4's journaled
HFS+, to whatever the current OS10.5 does if different?