Disable "...application downloaded from the Internet. Are you sure you want to open it?" on certain file types? Is it possible to modify which files Apple's quarantine warning pops up on?  Specifically I download hundreds of PHP files (web developer) and I'm tired of seeing "...is a script application downloaded from the Internet. Are you sure you want to open it?"  I don't mind the warning on most downloads, but don't want warnings on scripts I'm opening to edit.

FYI, Quarantine can be completly disabled with:
    defaults write com.apple.LaunchServices LSQuarantine -bool NO
and can be removed from existing files with:
    xattr -d -r com.apple.quarantine ~/foldername
If you download files from the internet into the ~/Downloads folder, you could assign a folder action to ~/Downloads via Automator:

Open Automator
Create a new Folder Action

As the action, drag over "Run Shell Script"

Assign the following shell script:

    for f in "$@"
    do
        test "$f" == *\.php &amp;&amp; xattr -d -r com.apple.quarantine $f
    done