Contextual advertising brokers are in the same frenzy as the [banner|pop-up|pop-under|interstitial] ad brokers of 5 years ago… Jensense reported on favicons at google adsense some time ago, Peter Forret saw “image-enhanced topical link units” from the Yahoo Publisher Network and I saw some neat “search within adsense” popping up (so it’s about search after all ;-) !):
Click for better/full view (the Dutch-language sentence in the upper left corner says: “Change to ads on“):
There are also search boxes within ad link units (an easy solution if the adsense server has no clue whatsoever what the page is about ;-) ):
Whereas the search results in the previous example are displayed inline, a search query within the link unit leads to a paid results page directly (as other ad link units do).