The easy solution is to keep a case on your phone. There are several companies that manufacture quality silicon/neoprene/leather cases which should protect the phone from the worst of the elements.
They will not, however, make the phone suddenly waterproof, so there is still a risk involved. Use of common sense applies at this stage. Don't use the phone in the rain, don't take it into the bathroom with you when you're having a shower (You'd be surprised how many people i know leave their phone on a shelf in the bathroom while they're taking a steaming hot shower - water vapour, anyone?!) don't go swimming with it, etc.
As long as you take care of your phone, it should take care of you in return.
I've personally got 2 phones. I've got the 5500, which i use at work more than anything else (I work on a nature reserve, so it gets a fair amount of abuse) and i've got an E65 for the rest of the time. Both of which have Krussel cases on them and i've had no problems with either phone