Here's a great piece of crossover Doctor Who fan art called TARDIS in Wonderland. I love how the illustration was inspired by Alice in Wonderland artist John Tenniel. The piece was created by ParodiesLost and it comes with the following note,
Upon reflection, it's seems only natural that the Doctor and the TARDIS would have made it to Wonderland and crossed paths with Alice herself-- as this previously unpublished drawing by famous Alice illustrator John Tenniel reveals!* And who wouldn't love to have been able to eavesdrop on any conversation he might have had with the Chesire cat!?! [*Statements may not reflect objective reality!]
This could definitly be a very cool concept for a future episode of Doctor Who!
Source: Doctor Who Tumblr (http://doctorwho.tumblr.com/post/26074274153/tardis-in-wonderland-crossover-fan-art)