Another from James Duncan Davidson: Story and pictures of his bulging MacBook Pro battery:
I told my neighbor, Greg, about it and he said “bring it on over! I want to see this!”. So I did. And as we were looking at it, and moving it about it as we looked at it, it started exuding a smell. A nasty burned plastic smell. And parts of it warmed up. Even though it hadn’t been in a laptop in probably well over a month, maybe two, it was suddenly going critical. The warm spots would fade to cool, and then others would appear and get hot. Greg and I looked at each other and decided now was the time to take it to the Apple Store for them to deal with.