Depending upon what aspect of AdWords you want to automate, you can look at various tools. As Megumi suggested, Marin is a good option for bid management. You can have a look at Optmyzr (optmyzr.com) to automate account management activities. Cyfe is another option to automate reporting and building dashboards.
There is many ways that can help you automate bid management:
I'll not recommend an automatization tool.... Adwords Editor is very good to manage multiples campaigns and accounts.
Optmyzr, no question. It was built by the ex-adwords evangelist at Google and is all about productivity. DM me for more info, we use it day in and day out on my team.