About potential java cell phone viruses:
Java is running on a virtual machine and the 'sandboxing' tecnique is used, therefore it's not very vulnerable to viruses. Sandboxing means the application is not run on the native os, but in a seperate platform which hasn't got all access rights to the hardware. So java is kind of a safe platform.

The cellphones use a stripped down version of java called micro edition which isn't enough too fully exploit the possibilites of the cellphone hardware. Therefore the phone vendors have added extra functionality specific to their phones. This functionality gives access to specific keys, access to address books, access to sms-messages and tcp connections in/out. I think here lies the biggest potential of creating a virus.

I've played a bit with one of these java phones (the Siemens M50) and it has quite a few possibilites. It's not easy to create a virus for it though, although I havent tried to do that specifically. To get access to tcp/ip with GPRS, the user has too agree to do this. It seems there is no way around, it's built into the hardware. The same with telephone list access & other phone specific things. The users always has to agree to the action. But.... There probably is ways around this, at least on some of the phones. I'm positive we'll hear about ALOT of exploits in the near future. The engineers ALWAYS forget about certain details and make mistakes.

If anyone wants to look at the programming SDK and the specifications for the Siemens phones, try this link: http://www.siemens-mobile.de/btob/CD...950,28,FF.html
You have to sign up to get access to the downloads.

As for other types of viruses, I don't think there are any. There was one way to exploit a phone however. If you had a computer with possibilites to send sms messages you could modify the sms control headers and send the modified sms to a phone. That would make the particuler phone (some kind of Nokia I think) crash. You had to remove the battery to make it work again, and then all the telephone numbers would be lost. (I'm not totally sure about the details, though).