I've stuck together a little page of various different GI settings examples.
Most of you probably know all this stuff already but, I figure this might be a handy reference point for people new to TG2 or, to 3D scene building in general.
You might just like to see directly the differences between GI settings.
I could sit for hours(and I do, it's you guys who make the pretty pictures in here!

) just playing with settings and testing them against each other to find out their purpose and uses, might as well document this one, since I think it could be a handy reference to some folks.
To the untrained eye, GI effects aren't all that easy to differentiate between, especially in a regular, built up landscape scene, which we mostly see coming from TG2.
Here, Terragen's GI settings are used in a general purpose illumination room made inside the program. The differences between various levels and options are very clear to see in such a setting.
Hopefully, this will go some way to help illustrate the outputs and to help anyone who isn't sure to get a handle on TG's GI system and, when to use what settings.
So, should you like to visit, here is the page link:
http://sites.google.com/site/d4nd310/tg2giCheers!