Macbook - keys not working

I have a white Macbook '07. Suddenly the majority of the keys stopped working. Some of the keys type the wrong letter/number.

I had cleaned the keyboard an hour prior with lightly moisted paper towel.

What happened? What can I do?

Did any water from the paper towel drip down in between the keys? Turn the machine upside down in a warm place for several hours with the lid open. Do not turn the machine on and remove the battery. Let's see if it dries out enough to get the keys working again.

Hi! No, no water went into the keyboard. It's been over 12 hours now, and nothing has changed...

Did you hit the Num Lock button? I think it's the F6 button on older keyboards. It'll change the right hand side of the keyboard to numbers or mathematical symbols.

Nope. It's not that :/

Then the other thing I'd check is the Language & Text (I think it's International in SL) system preference, Input Sources tab, and make sure you're still using the US or US Extended keyboard format and a different keyboard format wasn't accidentally selected.

I restarted, and I need a password to log back in to my account in order to change settings. But I can't type in the correct password due to the keys being this way!