snarky

snark¡¤y -- Pronunciation snahr-kee
adjective, snark¡¤i¡¤er, snark¡¤i¡¤est.

Chiefly British Slang. Testy or irritable; irascible.
Sarcastic or disrespectful; snide.
Sarcastic humor.

"He was being very snarky with me. Yeah, snarky. Its a word. Google it." - Dane Cook

Also a girl on Myspace and OkCupid defines herself as being snarky and she is actually pretty funny in a sarcastic way so its fitting of her too.