I don't recall seeing anything like this in pre-Leopard systems. After the upgrade to Leopard, many of my Terminal permissions listings now include the @ symbol at the end, as in drwxr-xr-x@. I'm not concerned or anything, just curious as to its meaning and any significance related to the new OS.
Actually, "+" indicates the richer permission model (also known as ACLs).
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 <filename>' to show them. It seems that a lot of Finder information, which ought to be stored in the catalog, is now in extended attributes. (Hmmm, or maybe it's actually still in the catalog file and just being exposed as extended attributes, which would make a lot of sense.)
Actually, "+" indicates the richer permission model (also known as ACLs).
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 <filename>' to show them. It seems that a lot of Finder information, which ought to be stored in the catalog, is now in extended attributes. (Hmmm, or maybe it's actually still in the catalog file and just being exposed as extended attributes, which would make a lot of sense.)
I have found that the @ symbol appears on directories (possibly files but I haven't looked) that I have changed the Finder's icon. If the following command is issued, the directory's icon will be reset to the default:
Mac OS X supports multiple permission models - there's the standard set of owner/group/other and read/write/execute, and a richer set that allows more fine-grained control.
ls uses the @ sign to indicate files are using the richer set and therefore what you're seeing is only part of the picture. You can use the -e switch to display the extended permissions.