To fill in a sentence,when there are no other words to describe the current situation. It is also commonly used to change the subject from the main point of of the conversation as a way of "getting out of the hot seat."
Person a: person b,when are you going to give me gas money?
person a: Huh!
person b: sumthin bout a hamsamich...
person a :o.0???
person b: =P
person a: Whatever man, just give it to me when you got it i guess...
person b: haha =)... ight den, i got u doe.
person a: yep.