I wonder what is the keyboard shortcut for these two combo boxs and specially the right part which list all the members of current class and is very handy for navigating a large class.
I tried to figure it out myself but I do not know the exact names to search for it.
The keyboard shortcut is CTRL-F2 which takes you to the left-hand combo. If you hover over each one in turn (at least in VS2k8) it shows you a tooltip which identifies the two combos as "Types" and "Members", respectively.
Pressing TAB will take you to the right-hand combo and CTRL-DOWNARROW will expand the combo for you.
That whole thing is called "Navigation bar" (Window.MovetoNavigationBar) and can be activated by default by pressing Ctrl + F2. There doesn't seem to be a shortcut for the right side of the navigation bar, so pressing the short cut key always takes you to the combo box on the left side. You can use Tab to jump between the combo boxes.