Water damage can prove disastrous to any electronic device, but you may be able to save it with some luck and... rice. Yes, rice.
Take the battery out if you can, and put the whole thing in a bowl of dry, uncooked rice. Because Rice has moisture-absorbing properties, if you leave it there for the night it could absorb it - and because rice is relatively large, it won't get inside the blackberry.
Know that this doesn't always work, as water can cause irreparable damage to the circuits. But if you took your battery out soon enough after getting it wet, you still have a good chance.