Change animation fps at certain times (i.e. slow down the animation for a moment) What I want is to fly by an object, and once we are really close to it, slow down time to give a nice look (animation of the objects in the scene is also slowed down) and then move on.

What this basically boils down to is this: we should have less frames per second at the 'slowed down' moment (less frames passing by in the same time means that the animation passes by slower) and then increase the fps afterwards.

Now, how do I do that? Or are there other ways to do it easily?
This won't accomplish exactly what you want, but you could always simply animate as usual, and then stretch out your IPO curves in the editor evenly so that, even though the FPS stays the same, the animation appears to slow down.

(Added bonus: the change can be gradual if you use this method).