Not exhaustive, but it should help you put a name to the odd face...

David Brent

Gareth Keenan

Tim Canterbury

Dawn Tinsley

Chris Finch

Neil Godwin

Jennifer Taylor Clarke

Keith Bishop

Keith Bishop - (Ewan Macintosh)

Keith works in accounts. In keeping with his occupation he is extraordinarily deficient in social skills and his answerphone message is a monotone joy to behold. He enjoys scotch eggs, suffers from eczema and has short term memory problems.

The Office Series 1 - DVD | VHS
The Office Series 2 - DVD | VHS
The Office Christmas Specials - DVD | VHS
The Office Complete Box Set - DVD
The Office Scripts - series 1 | series 2

BBC's Office Web Site
BBC America's Office Web Site
Martin Freeman(Tim)'s Web Site