Not too long ago in the not-so-distant past, I was making my way across the parking lot and into Big Lots (which, in this town, is found as a part of a shopping strip). On my way into the store, I noticed a vehicle with its lights on. Being the good citizen that I am, I decided to do my small part to inform the owner. What follows is an actual account of the conversation that I had as a result. The involved parties are the random worker who happened to be the first worker whom I saw upon walking into Big Lots (from henceforth known as RW) and me.
Me (to RW): Ummm excuse me...?
RW: *really annoyed and disgusted look*
Me: Ummm... I was wondering if you had any sort of speaker system or anything in the store for making announcements.
RW: *slightly blank really annoyed and disgusted look*
Me: Well, you see, the reason that I was wondering is that there's a black Honda out there with its lights on, and I thought maybe you could announce it in case they're in the store.
RW: Just because they're parked in the parking lot doesn't mean they're in the store.
Me: Ummm... *slightly stunned look*
RW: You see, there are lots of other stores around, they could be in one of those.
Me: Uhhh... yeah, I guess that's true...
RW: *Supreme look of Superiority before turning her back on me*
Me: Ok, well, thanks.
And yes, I do tend to use "ummm" a lot when I'm in a situation involving people whom I don't know.