Growing up in central Jersey, most towns had "custard stands" but most are gone now, yet several survive. In Monmouth County, there's the former Jack Frost
in Englishtown, now called Four Brothers
and Jersey Freeze
("We will be open next season" says the handwritten sign at the counter, so I guess it's gotten a reprieve on being replaced with a chain Italian restaurant) in Freehold on what used to be a traffic circle for Rt. 33 and Rt. 9 was a well-known NJ classic roadside stop on the way "down the shore".
Also, on a still somewhat rural (well, for NJ-but for how long?) section of Rt. 33, between Freehold and Hightstown, there's Jake's Cree Mee Freeze
in Millstone Twp. - http://monmouthdailyphoto.wordpress.com/2008/05/27/cree-mee/
perhaps best known on the 'net for being a setting of an episode of "Sex and The City" (where it filled in for a Long Island stop).
A few miles east (just past a bowling alley and horse farm), in Manalapan, are two small almost "trailer-ish" buildings where various businesses have come and gone with great frequency (spas, clothing boutiques, home improvement offices, etc). Recently one of them is being re-build and enlarged (possibly adding a second story or maybe just a facade) and a sign went up "Coming Spring 2009- Jake's Cree Mee Freeze Too!
". The "Too" implies it's in addition to the current business (possibly it'll be "all season", "eat in"?)- it would be a shame to lose a classic roadside custard stand.