I fell in the ocean the other day with my N900 in my pocket. It was turned off, but it was completely submerged. I immediately took the battery out and put it in a bag of rice, where it has been for a day and a half. Is there anything else I can do to try and rescue it before turning it on?

I'd recommend leaving it in the rice for another day or two. I'd also try a different battery if you have one. I'm not sure about the N900 battery, but some batteries will short out if submersed even if the piece of equipment they are in is not on.

You dropped it into seawater right? I think you might need to take it apart to get the salt crystals out. Searching google gives you recommendations of rinsing with distilled water or alcohol asap, and then drying it. Good luck!

Good point. I didn't think about it being dropped in sal****er.

Edit : Why is salt water considered an expletive ?

I will try rinsing it with distilled water. It has already been drying for a day and a half - is rinsing it likely to still be effective?

Mate whatever you do not turn your phone on for few days even with a new or differrent battery! Let it completely dry out! Use special alcohol containg liquid for cleaning getting rid of sea water and salt crystals its better then distilled water as it quickly evaporates after its done its job so it will quicker drying process! Put your phone completely submerged in a air tight container full of rice with the keyboard open obviously without the back cover on and facing upwards helps also put battery in there as well for a day or two! If you have central heating in your house then put it on top of your radiator facing upwards for a few hours with moderate warm temperature dont put heat temperature too high! Only after you are 101 percent sure then put battery in and give it a go and see if it starts up if it does you are lucky but if you see any sign of water on screen then imediately remove battery repeat drying process leave it for another day or two and check again! the longer you dry it safer it is and more chances of you not destroying the phone even if it was recoverable by voltage spike!
Oh and good luck!

"the longer you dry it safer it is"

may the key to get your phone back

also i have heard keeping the phone under a 100 voltage bulb for some days can dry out water(dont put it so near the bulb, lest it will burn the sensitive part of the phone)
Good luck!

Happened with me 3 days ago..but it was a glass of Iced tea which fell on my phone.. so i kept it for drying . Next day i start to try it..the Touchscreen is flickering and is not responding.. so i thought this is the end.. but i just kept it for drying one more day...and the 2nd day i started it..everything is working fine! :O ! the touchscreen, speakers ..everything.. !

I've destroyed my old K800 once when I came with it into swamp. It had to much sediment and corrosion. Maybe somebody out here can know how to make it not happen.