Lossy copying

Finder does a good job of preserving data and metadata.

If you find yourself using an environment that's not wholly compatible (some FTP servers fall into this category), then you may prefer to use something other than Finder.

However: please be aware that using applications other than Finder, to move or copy data, may lead to loss of metadata and/or extended attributes including but not limited to:

  • access control lists (ACLs)
  • Spotlight comments
  • file-specific application bindings
  • color labels
  • icon positioning
  • custom icons.

muCommander: a cross-platform file manager

Environments that are not wholly compatible with Finder may be friendlier to muCommander.

http://www.mucommander.com/
copy or move from fork-aware system: forked data is lost

BlueHarvest

allows you to keep your disks and servers free of Mac "trails"

http://zeroonetwenty.com/blueharvest/

the cp command

In Mac OS X 10.5 (Leopard) the options for cp include:

     -X    Do not copy Extended Attributes (EAs) or resource forks.

Mac OS X Manual Page For cp

Mac OS X 10.4: How to prevent .DS_Store file creation over network connections

http://docs.info.apple.com/article.html?artnum=301711