The show started back in 1963 and is now on its 10th Doctor, but it still has the same iconic TARDIS spacecraft, as well as that fictional extraterrestrial race of mutants called Daleks. These icons are mirrored on the pens, which are available in both the TARDIS and Dalek styles.
As an extra bonus, the pens could easily inspire a round of Abbott and Costello-like "Who's on First?" banter:
Annoying co-worker: "Whose pen is that?" (Read: Who's pen, is that?)
You: "Yes it is."
With enough clever banter like that, you could hear surprisingly loud phrases like "Seek, Locate, Annihilate" and "Exterminate" not only from the black Dalek pen, but from your new ex-friend.
The sounds emanating from the blue TARDIS pen are nearly identical to the classic and somewhat cheesy sounds of the "real" TARDIS. Both pens also play the "Doctor Who" theme song. The pens retail for about $12.