When people speak at a normal rate of speed, the long form becomes reduced. going to = gonna want to = wanna ought to = outta (I'm guessing at this one. It might mean "out of" as in "I'm outta here" = I'm leaving.) have to = hafta should have = should of (could, would) (Many young people don't know that "should of" is completely non-standard English. The reductions happen when speaking. People often type the reductions when they are texting or chatting online. I guess it saves them time. If they are really poor at keyboarding, then perhaps it saves them two seconds or so. The reductions are NEVER used in standard written English. They just aren't accepted in any kind of academic, business, journalistic, English-- EVER. : ) If you use the long (standard) forms when texting or chatting, no one will think it is strange or out of place. If you use them in formal situations, people will judge you and your competence.

So now you know - OUTTA means "Out Of" - don't thank us. http://www.internetslang.com/OUTTA.asp