ATi-card users have noticed very long waits when selecting objects in the 3D view. Now that I got myself a new machine featuring an ATi HD 2600 Pro I noticed it too. The old mantra was "update drivers, turn down hardware acceleration, turn off goodies", but some further research led me to a page created by Trent Apted. It explains that a certain operation, on which Blender relies quite a bit, has been very slow since end November 2007. With a small test program this can be verified. I did that too, and to my delight I have now a Blender that is usable again, even on my ATi-card.
Since I'm on Vista, I thought, why not make a screencast of how I updated the drivers - it's not always that obvious. So here you go.