Please tell me i want to know I want to blick all the low paying ads i imagine ads like ebay and shopping.com pay low?
yes it is possible if you have low traffic. Use any adsense tracking script. It will tell you which ad is clicked and because if you have low traffic then you will be able to match ads and earnings if you are using channels specially url channel.
There is no real way to find it out. only way is for you to guess! There is an tool @ ... http://uv.bidtool.overture.com/d/USm/search/tools/bidtool/index.jhtml But the above just gives an very high level idea of which keywords pay howmuch. But Ad rates at AdSense program may vary considerably.
I'm not sure if it's allowed, but if you have an adwords account you can use one of the adwords tools (I don't wanna give the name cause I don't want to get in trouble if it's not allowed, I'll let you look for it ) to see the bid amount needed for top placement for a particular keyword... I don't know if that helps but I think it's better an actual dollar amount than just seeing which keywords rank highest IMHO
Blocking low paying ads is a short sighted stratagy. Just because it's low paying today doesn't mean it will be tomorrow.