Torchwood House (tie-in website)
From Tardis Wiki, the free Doctor Who reference
The website of Torchwood House provides information on the features of the house and history of the house, which has been opened for visits by the public. The site was launched in conjunction with the airing of Tooth and Claw.
Behind the scenes
Under the "View Lunar Surface" link on the Observatory page, there is a reference to the Tycho crater of the moon being a source of "unusual signals" since 2001.
The "Weddings Quotes" page features a photograph of Bernard Cribbins at a wedding. The site launched more than a year and a half before Cribbins first appeared as Wilfred Mott. (TV: Voyage of the Damned)