One of the side effects of increased cell phone usage is the risk of telemarketing calls and junk text messages (NY Times, free registration req’d). Given that in the US users pay for incoming airtime and often for incoming text messages such call are not only annoying, but cost users money. There is absolutely no excuse of spam text messages. But with cell phone numbers often indistinguishable from land numbers and cell phones becoming some users main phone numbers, measures must be put into place to prevent unwanted telemarketing calls. We need a simple, effective way to block unwanted telemarketing calls on all our phones.