The latest in vogue saying is "just sayin". In the past few months, I've read it, heard it, and experienced it first hand from Jenna. It's a sophisticated "in your face" snarky phrase and in the audible form requires a punctuated dialect with a toss of the head and emphasis on elongating "saaayinnnn". Maybe even a flip of the "talk to the hand" gesture for even more emphasis.
I'm a little behind the times after listening to Scott Simon's NPR (Dec. 18, 2010) rant on the phrase. Scott says "Saying, "I'm just saying," puts a fire escape onto the end of a sentence. It lets you express a stern — even rude — opinion, but not really. You're just saying. It invites the listener to discount what we've just heard, even as we're reeling from it."
Next time you hear "just sayin" respond "just ignorin".