AdWords Scripts now support 
negative keyword and 
excluded ad placement lists, and the ability to share them across campaigns. Follow these links for implementation details and code examples:
We have also released a new solution named 
Master Negative List that uses this feature to maintain a master list of negative keywords and placements for AdWords accounts. The list of negative criteria can be managed from a spreadsheet. Separate versions are available for 
AdWords accounts and
 manager accounts.
Special thanks goes to Terence Nip, who implemented this feature during his summer internship at Google.
Give this feature a try and let us know what you think! You can post your questions and feedback on our 
developer forum.
 Anash P. Oommen, AdWords Scripts Team
 Anash P. Oommen, AdWords Scripts Team