Opt out from DMOZ description
Most description from SERPs generated from top search engines came from Open Directory Project (ODP) and not from the actual site description. Now, most of the site owners do not like this to happen since most of the descriptions there are outdated or maybe incorrect. Google now supports META NOODP
Adsense Section Targeting
Right keywords on your site displays the right ads. With section targeting, you could redirect google bot to which portion of your site that has more relevant content, most probably a paragraph with your main keyword. This would greatly lessen the PSAs displayed on your site. Although google bot automatically