Cory Doctorow is in love with an app for his Android G1 smartphone which shim’s the dialer of android devices to make calling card calls without him having to dial the entire series of numbers to get the cheap rates:

…today I downloaded my first game-changing app: Android Calling Card, which auto-dials any cheapo calling card you buy down at the corner store, and the PIN, and then any number from your address book, automagically. It supports multiple cards (the cornershop card-array is very country specific — Eastern Europe, USA, China, and other nations all have their own cards) and unobtrusively shims itself into the phone’s built-in dialer app.

I just used it for an hour-long overseas conference-call — the kind of thing that used to cost me £20 or £30 — and the total cost was £0.51!

Of course, I wonder how far behind it the malware version which shims the dialer to route your call through Tunesia or some other hyper-expensive billing fraud channel is. And what are our options (if any) to protect ourselves against it?