Google posted on Google+ that there is a new and easier way to implement call conversion tracking with AdWords. Now you implement one snippet of code per landing page and Google will dynamically serve the right number.
Google said that all you need to do is tell them "the phone number you want to track calls for and then install one auto-generated conversion tracking tag on your website." Google said that "this means you no longer have to separately add a Javascript snippet for each instance a phone number appears on your landing page." Clearly this "works best if you only need to track one phone number for a given landing page," Google added.
This can save time for some of you who use call tracking conversions with AdWords.
Forum discussion at Google+.