When David Tennant left Doctor Who , the cast and crew made a music video of "(I'm Gonna Be) 500 Miles" by The Proclaimers for the wrap party. Footage of Tennant hanging with the band surfaced a while back, but here's the whole shebang. Looking good, Ood.
UPDATED 10/31: Also, here's a musical love letter from the wrap party David Tennant, Catherine Tate and John Barrowman composed for Russell T. Davies and Julie Gardner. Six minutes of Victoria Wood-channeling madness. You can find the lyrics on the YouTube page.