Many times we dont wish to receive calls or SMS from a particular person or number and wish we could block it, such feature was not available on Windows Phone till now, but from now onwards Windows Phone 8 users using Amber update can do this.
If you want to block any number then all you have to do is long tap on number and then select Block number from screen or you can navigate to Settings->call and SMS filter and block number from call or SMS. You can also pin this to your live tile shortcut.
This feature is already available on Android via third party apps, and Apple has introduced this in iOS 7 which will be available by year end.
Thanks to Harshita for this news