(no subject)

Can anyone name a bird that's light blueish-greyish on it's back, white on the stomach, and has a wide black streak down the center of an otherwise white head? Possibly a type of woodpecker, since I saw it hanging onto the side of a tree and giving it a couple pecks, though it might just be that there was a tasty-looking bug crawling up it. And it's small, not a blue-jay.

The descibed bird flying around in my backyard and annoying the hell out of me, since I could swear that I know what it is but the name just won't come to mind.