>I know basically what a hanken mono cel is,
>but all promotional artwork pieces aren't done as
>cels, are they?
Most still are.  Some will be combos of CG and cels.

> How do you tell, for instance, if an image in an >anime-specific artbook is actually a hanken cel?? 
Often times, I look at credits.
They'll have credits like "Cel Genga: Fujita Mariko Finishing Work: Koga Makoto" or something.
If something is digital, they'll usually say "CG Effect: "

>I have two art images specifically in mind, and
if they are hanken monos, I'd literally die to
own them (though I doubt the odds of my finding
them are, ugh, one in a'zillion O_o)! But... how
do I tell if they're cels as apposed to another
>form of art...??
Let's see em!