Come iOS 7, you'll be able to block unwanted callers. But what if you have jerks, salespeople, and Crazy Great-Aunt Rita calling you nonstop now, and iOS 7's fall release date seems like just too darn long to wait for some semblance of phone peace? There's a solution.
An anonymous Hints reader suggests creating a new contact. The hint provider made a contact called Don't Answer; you might instead choose Jerky Bonehead or Loser McShutupington--it's your choice.
To do so, go into the Contacts app, tap the plus (+) icon at the upper right, and create the new contact without any other details like a phone number.
Then, the next time you get a call from one of those annoying folks you don't want to speak with ever again, add their numbers to your contact. Find the number--you can see it in the Phone apps' Recents tab--and tap the button at the right. On the screen that appears, tap Add to Existing Contact, and choose your special contact name, and save.
Next time a call comes in from the nogoodnik, you'll see your chosen name and know not to bother answering.
Commenters on the original hint offered up a clever bonus: Create a silent ringtone, and assign it to that contact. If you have GarageBand installed on your iOS device, you can create a silent ringtone in mere minutes.