I've put up a test page where you'll find 2 multiple select boxes. You should be able to select multiple options without holding that damn CTRL button. The jquery built into Drupal and my small code snippet takes care of this for you. Please test it out and leave a comment when:
- you experience problems. Important, I need to know which browser/os you're on, otherwise, the comment is useless.
- you have suggestions to optimize the code.
Please test, so I can post this on the Drupal/Jquery forums. Open source can benefit from all our help!