Does a call filtering app exist?
 

Hi Folks,
one of the very few apps that I am missing from either symbian or apple land is a call and sms filter app. In my job I get pestered by recruitment agencies daily and having an application where I can create blacklist and whitelists for callers I want to block or hear from is ideal.
I am thinking of something like iBlacklist on the iPhone or Call Blocker on Symbian.
Is anyone aware of any apps in this area - which either exist or are in development?

It may be something I look to develop if nothing exists...

thanks in advance for any responses