Seeing as this just came up *again* recently... and no I didn't read through the 1700 posts in this thread to see if this had already be offered.
One of my major *PEEVES*.
When I get around youth (anyone) that can't talk without adding in a "Like", "um", or "yaknow" between every other word. OMG, that drives me crazy. I've gotten to the point where with my thumb and forefinger, I make an L and put it on my forehead in the typical "Loser" sign. When they ask me why, I tell them that it's my dislike for *like* and explain.
The best part is if they will take the bait, to ask them to tell me something *without* using, "like", "um" or "yaknow" between each word. It's pretty funny when they can't do it or the first word out of their mouth is "UM"!!!
It's a very bad habit and one that is very hard to break, but I suspect their future worth (monetarily) will be greatly impacted if they dont break the habit.