Karen and Brian Johnson found this American Golden-plover, above, at Heislerville, NJ today, Friday, April 12 2013. Compared to a Black-bellied, it has a finer bill and darker cap which contrasts with the pale eyebrow. It is also slimmer and longer winged, with wings projecting slightly past the tail (on Black-bellied the wings are about even with the tail.) Compare the Black-bellied, below.
In the view below of the golden-plover, you can see the golden-plover doesn't have much of a wing stripe, while a Black-bellied would show a prominent white wing stripe.
[Karen and Brian also had this Black-necked Stilt at Heislerville - pretty good evening of birding for them!]