www.axeltabs.com 5000$

roundhound.com 100$
codearcher.com 100$
linuxarhcer.net 100$
guitar-tabs-lyrics.com 100$
divx-subtitles.org 100$

axeltabs.com makes 250$ from google adsense per month, and has 35k page views per day.
other sites make quite small traffic but stil.. together they make 1-2$ per day from adsense.