Create white list of people from whom you get audible ring, and silent all the rest.
Mobile users often get confronted with a situation where they tend to miss some pretty vital calls while their mobile sits ‘silent’ in their pockets. Similarly, there are situations where you may get lots of junk calls while you anticipate an important call from some of your important contacts, thereby having to keep your mobile in the ringer mode.
The solution to this perplexing situation has finally arrived in the form of SemiSilent – an Android app that allows you to set your device to ring for contacts of your choice even if your mobile phone is in Silent mode. So, in essence it basically creates a white list of people who can give you audible rings while rest of calls are muted.
Grab the app @ Android Market