Ad sitelinks: Google adds extra links to Adwords adverts
Google is allowing advertisers to include extra links in their Adwords adverts (the paid results that appear on the Google results page).
Here are some examples:

Direct Line advert with Adwords sitelinks

Barclays advert with Adwords sitelinks

Which advert with Adwords sitelinks
The layout can go a bit wrong
If your browser window is too narrow, the layout can go odd:

Adwords sitelinks: layout goes odd in narrow browser windows
Google's explanation
According to Google's adwords blog, you can:
provide additional links to content deep within your sites. Rather than sending all users to the same landing page, Ad Sitelinks will display up to 4 additional Destination URLs on your search-based text ad for users to choose from.
With Ad Sitelinks, you can point to specific information on your site such as gift registries, special deals, holiday or event-related promotions, and store locators. Early participants in Ad Sitelinks, like Priceline.com, found that presenting multiple link options made it easier to direct users to relevant information on their sites, driving them deeper into the conversion funnel.
Currently, the option to set up Ad Sitelinks will only appear for advertisers whose ads meet a certain high quality threshold.
Even more clutter on the Google results page I say ...
[...] extended its Adwords sitelinks recently. And they also appear to be allowing advertisers to play around with formatting - it seems [...]