This is not good news.
CNET has the details on a proof-of-concept demo that shows conclusively that it's possible to take over your cell phone, even when you're sleeping.
The attack is actually rather simple - the attacker sends your phone an SMS message that automatically opens a web browser that directs your phone to a malicious website, where malcode is downloaded to your phone.
Depending on the malicious code involved, evil-doers could suck the data off of your phone, monitor your calls, or perform any number of tasks once they gain full control.
There are several other attacks detailed, such as directing the phone to a wireless network so that email and other authentication credentials can be sniffed and captured. Sounds like it's time to step up the R&D around mobile security.
As more folks ditch their landlines and go all-mobile, cellular communication becomes a very large attack surface, and the breadth and depth of incursion vectors is quickly becoming realized.
Proof-of-concept demo for hijacking mobile phones