OS X.6 - unquarantine downloaded files:

If you download files OS X adds a flag to quarantine these files. It will cause the warning " has downloaded the file at from .". This can be quite enervating when you download a lot of files via e.g. FTP. To get rid of the qurantine-flag on all files use this command in terminal:

$: xattr -r -d com.apple.quarantine ./*

You can also use the Automator-droplet (drag the folder that contains all files to be unquaratined):

Download unquarantine.zip