Q:

How can I find the value of the "Visual Effects" setting using the command line?

On 10.04 (and other versions, but I am asking about 10.04), going to
System ➜ Preferences ➜ Appearance and selecting the Visual Effects tab shows possible values of None, Normal, and Extra. How can I query from the command line what the current setting is?

A:

Yes, you can. If you are using GNOME, then there is excellent gconftool command.
Try
gconftool --get /desktop/gnome/session/required_components/windowmanager

It'll return metacity when setting is "None" and compiz for "Normal". At least in my Ubuntu 10.10 only difference between "Normal" and "Extra" was "wobbly" in plugins list.
Try
gconftool --get /apps/compiz/general/allscreens/options/active_plugins

to get list of plugins. Output should be something like

[core,ccp,move,resize,place,decoration,dbus,mousepoll,gnomecompat,png,svg,imgjpeg,text,commands,neg,wall,snap,animation,scale,scaleaddon,expo,staticswitcher,regex,resizeinfo,workarounds,ezoom,vpswitch,fade,session,shift,wobbly]

for "Extra" visual effects.

