In a view with lots of catagories and sub catagories, navigating by pressig the twisties can be a real pain, especially if your mouse is not too great or playing up. So I use the keyboard alot sometimes, and I've been using these for a long while. You might find them useful.
- Expand all & "+" (plus)
- Collapse all & "-" (minus)
- Expand selected and children "*" (asterix)
- Expand selected "+" (plus)
- Collapse selected "-" (minus)
p.s. they work best on a standard (i.e. non-laptop) keyboard.