There will be no click to call feature in adwords after december 3 20007. That means the time I am posting this information, click to call feature is no more.
Find the comments from google:
This ad format will no longer appear in Google search results. If you have active click-to-call ad campaigns, they will stop running completely after December 3, 2007. Statistics from click-to-call ads that you have already run (including clicks, impressions, and CPC) will still be included in your reports until January 9, 2008.
The click-to-call ads trial was an experiment designed to measure advertiser interest and user adoption. The experiment has ended, and well use the results to improve AdWords and build more solutions for advertisers who value phone calls.