Fresh off the boat, someone from across the ocean, from another land, difficulties conforming to the new culture and speaking a new language. Used to describe stereotypical behavior of recent immigrants. Often used to insult their use of broken English.
Fob is also known as Fresh Off the Beehengi, for all of you that are korean...if you're not, beehengi is plane. I think the Fobs are the ones that made this word up because how else would you know the word beehengi if you aren't a FOB?
The word FOB actually stands for "Free on Board", and is a term that was used (during some time period, and may still be used) for stowaways on ships (and possibly trains as well).