Number blocking in cell phone

Cell phone have became a commodity these days. Every one have one. No mater how smart these cell phone manufacturers are I still see there is a feature that they can add.

Every one of us use IM and E-mail. All such software have blocking list. If u get a IM or mail from one person in your blocked list..your software will automatically block it and may delete it also.

Then why not there is such a feature in the CELL PHONE.

Why I am not able to block any number? This feature works just like IM softwares. When ever u get a call from any such number it will automatically reject the call.

Ironically there is no need of any hardware change. It is just a software that dose all these.. Then why they have not came up with such thing yet?

I may have seen around 15 to 20 different models of phones till now. None of them have this small feature till now as far as i can remember. Do your phone have this feature?

If you are working in a company that makes cell phones ..make sure that ur next phone to have it..its your duty.

If you have any good reason ..please let me know..