-rwxr-xr-x@ meaning

Assuming you're using OS X (newer than 10.4), the @ symbol denotes the file has extended attributes associated with it. (See Stewie's answer for detail.)

To list the extended attribute, use

ls -l@

From the man page for ls:

-@  Display extended attribute keys and sizes in long (-l) output.

You should see something like the following -

(somesystem):~ user$ ls -al@ /
...
drwxr-xr-x@   6 root   wheel       204 Sep 27 12:00 private
 com.apple.FinderInfo       32

If you need to dig deeper than that, use xattr -l

The "@" sign -- which is not documented in the manual page for ls(1) indicates that the file has extended attributes. You can use the command 'xattr -l ' to show them

Quote from : http://en.wikipedia.org/wiki/Extended_file_attributes

Extended file attributes is a file system feature that enables users to associate computer files with metadata not interpreted by the filesystem, whereas regular attributes have a purpose strictly defined by the filesystem (such as permissions or records of creation and modification times).