Written Ν and ν (or for older browsers, approximately "N" and "v")
"NU" is the ISO 3166 Digraph [two-letter] country code for the New Zealand dependency of Niue.
General Yiddish? interrogative as in "So, nu?"
"nu" stands for "naked" in French and for "now" in Dutch.
Also used as a short form of new, as in [Nu Metal]?, [Nu Jazz]?, and (I guess so) Nupedia