There appeared to be a TARDIS in Sundays Sherlock Hounds of Baskerville, if you click the picture you can see it in High Res, on closer examination it looks like a lorry cab to me though, even so whats a lorry doing on a deserted moor? Something to do with the production crew perhaps?
Here is the area zoomed in...
TARDIS, but High Resolution fixes all! IMHO it is defiantly NOT a TARDIS, although it may not be a lorry, and other ideas anyone?
EDIT - Moffat on Twitter: "Sue says that isn't the TARDIS, it was a lighting thing. But by my cuff links, what ELSE could it be???" - This isn't a "trick of the light", its a solid object!
Thanx to PCJonathan for the grab. This is NOT photoshopped etc. in any way, I have increased the brightness a little though :)