Taking a marketing campaign from traditional vehicles such as TV and radio and tying it into internet vehicles is still a stumbling block to many marketers. I have only seen one commercial in the U.S., by Pontiac, that invites the user to Google them (actually shows 'Pontiac' being entered into a Google search box).

Clever. Instead of showing a URL at the bottom of the screen where you may or may not see it (they are often at the bottom of the screen in small print or mentioned once in a radio spot at the end - when the announcer is speaking quickly sometimes) they visually show a search in progress. From this point they can use SEO and PPC combined to, again drive their message to the user and then, engage them interactively where they can guide they user to take a desired action.

This is the cross-over that will server marketers well until the home PC and broadcasting are combined in the not-too-distant future.