The David Tennant Treat 4 Today is part of an item which was posted on Anglotopia.net.
It is an interview with Nick Grifiths who is the author of the book Dalek, I Love You which has a quote from David Tennant on the cover.
Click here to read the whole interview but the most interesting part is when Nick was asked how David wrote the cover quote. Nick explained it as:
"I was writing for the Radio Times while I wrote the book, and interviewed the show’s stars many times, including Tennant, who was never less than lovely. I asked him if he’d mind reading the book and giving a cover quote, he kindly said yes. “A very funny book for anyone who grew up wearing Tom Baker underpants – I know I did,” he wrote."