Google has announced new mobile advertising options to target the iPhone, G1, and other mobile devices with full HTML web browsers.
Advertisers can now create separate campaigns that are targeted specifically toward mobile searchers with smart phones. You can write mobile-specific ads and get performance data separate from your other AdWords campaigns.
This new mobile targeting is turned on by default for current AdWords advertisers. To throttle it on or off, look for the “Device Platform” option of the “Networks and bidding” section on the “Campaign Settings” page in your account (shown above). A checkbox lets you turn this mobile targeting option on or off. Barry Schwartz reported on this about 10 days ago on Search Engine Roundtable, when some advertisers began seeing the new option in their AdWords accounts.