We haven't had a Casual Friday in a while, and that's a tragedy that will be rectified now by some quality business comedy, courtesy of Don McMillan. He's one half engineer, one half comedian, and his office-related humor is well worth watching, especially if you've ever seen a bad PowerPoint presentation. Caveat: These are standup videos, so expect the general qualities of standup comedy, e.g. stereotypes, that may make them unsuitable for office viewing (in case you work in an un-fun office).
Last but not least, Don's magnum opus: Life After Death By PowerPoint