BLOCKING??

is there a way to block numbers from residential line?

pick up the phone and listen a moment...if it sounds like no sound on the other end, hit the  #  button on your phone six or more times as fast as you can, then hang up.  if you do it right, their automatic dialing system thinks your phone is dead and deletes your number from their call list.  works often enough to give it a try.

Some phones will let you specify rings and add your own rings. Just add your own "ring" that is no sound, then specify that for callers you don't wish to hear from. Others will simply let you designate no ring for certain numbers. Only thing you have to watch is not to pick up the phone while a call in is in progress.

thanks, I'm going to try that.

Yes.
Your traditional landline phone company offers such a service, but it is (I suspect intentionally) not very good.
Some VOIP providers have such services, and they range from fairly useless to completely excellent.
Some Panasonic portable phones have a call blocking ability which is pretty fair.
For the tech heads with an old unused computer lying around, there are even better options, just start reading about telephony and you'll find them * .

Most major landline phone provders have blocking features. Here is a good article: http://www.ehow.com/how_5707264_block-phone-number-calling.html talk about one of the features. I am with AT&T, and have activated "Anonymous Call Blocking" and "Call Blocking". So far so good, but it's just been 2 days.

The problem is with AT&T you are only allowed to block a maximum of 20 numbers.  Also, if you block a number that you know is a telemarketer, they usually have several lines that they call from, and you need to block each of their numbers, which adds up quickly to 20!  It does help some, though.