Some people have been quite surprised that N95 has a built-in accelerometer. I'm not, I've known that since the first day I got it, since the camera knows in which position it is. However, I wasn't sure if it's 1D, 2D or 3D and how accurate it is.
Now there are some information and demos available of the accelerometer. Unfortunately Nokia hasn't released the whole API (you only get information about one axis, and only 4 values). I hope they will soon. This will enable us to do many cool things with the N95.