Problem: Many of my friends are moving to OS X and are frustrated that, unlike Windows and *NIX systems, copying/moving a folder (with sub-folders) deletes the destination folder if a folder of the same name already exists at the destination.
Question: Is there a way to hack the system (or install a plugin?) so that it by default copy/move operations merge the source and destinations instead of outright wiping out the destination and everything inside (with no option for recovery)?
EDIT: Based on your clarification, you're looking to merge two directories. See this question for more information. There's no built-in way to do that using the OS X Finder.
As an alternative, you could try using standard unix tools like rsync, which are available via the command line. But this is not a very "Mac like" solution.
I'm not sure what you're asking, because when you copy a folder from one place to the other, nothing is deleted at all. I assume you're talking about copying a folder from one location to another where a folder of the same name already exists at the destination? If so, The Mac OS X Finder will show you a warning, it won't delete anything without your permission.
If that's not what you're asking, please edit your question to clarify, and comment on this answer asking me to update my answer. Thanks!
defaultcommand, and there's nothing under there that does what you want. :-( – Josh Dec 10 '10 at 17:03