*I'm going to...* Originated as a result of the lazy dialect of the citizens of the Northwestern United States. Imunna -- eye-mun-na (spoken quickly)
Imunna go take a nap.
A term meaning that your going to do something. A combination of the words I'm and ganna. Proof that Americans are getting better and better at butchering the English Language.
Larry: Imunna go to the mall.
Gena: Imunna go get a drink