If you get annoyed by the “blah is an application which was downloaded from the Internet. Are you sure you want to open it?” prompt on OSX, head over to this guys site to get a script that removes the downloaded file attribute from the file
http://henrik.nyh.se/2007/10/lift-the-leopard-download-quarantine
Short version: Save the file http://henrik.nyh.se/uploads/Unquarantine.scpt into your ~/Library/Scripts/Folder Action Scripts
In your downloads folder right click, Configure folder actions, tick “Enable Folder Actions”. Attach the “Unquarantine” action to the folder.