If you are going from delhi to agra ,you will find one CNG Filling station in mathura near to agrawal restaurant on NH-2.this oulet is opend recently from 1st of october 2011,and in agra you will get 4 cng filling stations,2 cng pumps on national highway-2 and rest 2 are in city..
thanks and regards,
vishwajeet chaudhary