when I search google web for "san francisco lawyer" I see one of the listings in the 10 pack having a yellow icon and a link "visit website" under the listing and "sponsored" after it. I've seen other similar sponsored listings with a link to their coupons...what's all this about? Is this done through the LBC? Or adwords?
I believe these are different from the ad extensions in Adwords. When you check in Google maps, the adwords extension listings will have a brown icon that shows a window with more info (and "sponsored listing" in the top). But these sponsored listings from the 10 pack will have a yellow icon, and when you hover it it immediately shows a link to go straight to their website (or coupons section etc.). Is this new? How are they getting those sponsored links in the 10 pack?
This is called Google Tags and it's not done through Adwords it's done through Google Places (previously LBC).
It only costs $25 a month. But be aware it won't help you rank any higher so if you're buried on page 3 of maps it won't help much. However if you have a 1st page listing in the 7 pack it can really help your listing stand out, as it does in the example you shared.
Here's the Google announcement from when they expanded it to more cities. It covers the cities where Tags are currently available and some of the uses. It's not just for coupons.