News is making the rounds about the first worm to infect Symbian Series 60 phones (Nokia 3650/6600, N-Gage, etc). The link posted even has a few screen shots of this proof-of-concept worm in action.
Like most worms/trojans of this type, it relies on the user to actually install it. Why anyone would just install something beamed to them via Bluetooth is beyond me, but it happens all the time with mail attachments in the Windoze world. P.T. Barnum's words were never truer than they are today... There's a sucker born every minute.