U.u is a facial expression used in texting, ect. This particular face usually means 'what do you think?' (sarcastic tone), though different people use them in different contexts. This link may help: http://www.urbandictionary.com/define.php?term=emoticon :)

U is text slang which is commonly used in Internet domain. U means short form of YOU. Hope it helps to understand better:)

U.u is used in chatrooms to emote disappointment or irritation.

Nobody cares =)

i mean that my skype is ash_200050