The K-Touch Tianyu B832 is light on features in the traditional sense, but has one ability that’s important when you truly need it. The phone lets you program five numbers into the notification list, so that when it detects that the SIM has been swapped out, it’ll send text messages to those five numbers.
If one of the five numbers then replies with an SMS, the phone locks itself until something happens—the original SIM is put back, perhaps? Other than this lockdown feature, the phone has TV-Out, MP3/WMA/AAC playback, WAP browser, JAVA, and is only available in China/Hong Kong.
Tianyu B832 [RingHK via Slashphone via Uber Phones]