A buddy of mine is a recently-relocated NYC native pining for Mallomars. They're in season at the moment, but I doubt they get distributed by Nabisco very far beyond the tri-state (Jersey / NY / CT) area.
Is there some local retailer who caters to such exotic fancies? (I never had them as a kid, so when I sampled them as an adult, I thought they were good, but they held no mystique or nostalgia value for me.)
I suppose he could always order them online: http://www.marshmallowcookiesonline.com/ $12 a pop for a box of Nabisco cookies, though: ouch.