Sorry for the lousy photos, this guy flicked about a lot. Black on top, white belly and white bars under its wings only visible when in flight.
Made a sound like a chipmunk.
Some kind of Bunting?
Resin Northumberland, United Kingdom(Zone 9a) Nov 07, 2010
Yep, Dark-eyed Junco (which is a species of bunting, family Emberizidae)