I hope no one objects to my poaching on this thread.

Here's an interesting battery report. I have seen many, many claims here about exploding batteries. These are almost always directed at cheap third-party batteries and how dangerous they are. The exploding battery is always a report -- the person it happened to is never the poster. Since I have used non-Nokia batteries for years, going back to my N800, with no problems, it always irritates me. The dangers are quite small.

However, I finally ran into a credible account of an explosion in a customer comment on Dealextreme. Here it is:

"Used this in my car that has got a fully working 24V system. I bought two of these but both blew up after charging the original Nokia N900 battery. I had it connected for about one minute when I heard I surprisingly loud boom and then I smelled the smoke."

So here we have a credible explosion report on the N900. But, as you will have noted -- it is with the original N900 battery! However, I guess it was the charger that blew up, not the battery.