- 22 May 1855: A gang of thieves lead by the enigmatic Edward Pierce steal £12,000 worth of gold bullion from a railway train en route to the Crimea. It is noted that Sherlock Holmes was the only Londoner to ever memorize the entire railway schedule. From Michael Crichton's historical novel The Great Train Robbery. It's an odd thing to note about a fictional character in an unrelated novel, isn't it? Too bad Holmes was only about seventeen months old at the time of the crime.
- 5 November 1955: Marty McFly, a time traveler from 1985, is upon his arrival mistaken for a space alien, due to his unfortunate resemblance to the cover illustration of Tales From Space, a comic book owned by one of the witnesses to his arrival, one Sherman Peabody. From the 1985 film Back to the Future. This particular issue of Tales From Space was apparently quite popular, as it was reprinted at least once during the next half-century.
- 25 August 1967: A little girl is kidnapped from Innsmouth by (as it transpires) an inhabitant of the underwater city of Rapture. From There's Something In The Sea, the online background for the video game BioShock 2. Curiously, the reports from this event put Innsmouth in Rhode Island instead of Massachusetts, but as there's no actual town by that name in Rhode Island either, I'm chalking it up to either a subtle misdirection by the game developers or a transcription error by Mark Meltzer.
- November 1986: The Notion Club, a literary society from Oxford, discusses the fictionalized account of Dr. Elwin Ransom's 1938 journey to Mars. From J.R.R. Tolkien's unfinished Notion Club Papers. In addition to mentioning Ransom's book Out of the Silent Planet, the Papers also discuss the Club member's psychic encounters with Numenor, strengthening the connection with the Cosmic Trilogy.
- 1998: Visiting extraterrestrial Harry Solomon reads a familiar-looking Tales From Space comic. From the "3rd Rock From the Sun" episode "The House That Dick Built". This appearance establishes a link among that TV show, Back to the Future, and Heroes.
- Autumn 2005: While fighting some vampires, Chicago-based wizard Harry Dresden tells Inari Raith to "make like Buffy". Later in the fight he tries to stab a vampire with his broken blasting rod, "Buffy-like". From Jim Butcher's "Dresden Files" novel Blood Rites. The connection to "Buffy the Vampire Slayer" is somewhat tenuous, since the reference is immediately followed by Harry thinking that staking vampires with broken sticks "works better on television". Still, Harry never does come out and say that Buffy Summers is only a TV character, and while later in the series Thomas does wear a Buffy T-Shirt . . . so has Buffy.
- 7 - 10 October 2006: Several people read the Tales From Space comic first seen in 1955, including technopath Micah Sanders and an unnamed student at Union Wells High School. From the television show "Heroes", which provides the major link to the Back to the Future series.
- Summer 2011: Harry Dresden muses that the universe contains "terrors that the Black-Goat-with-a-Thousand-Young wouldn't dare use for its kids' bedtime stories." From the Dresden Files novel Turn Coat. "The Black-Goat-with-a-Thousand-Young" is, of course, one of the titles of the Lovecraftian entity Shub-Niggurath. This reference also serves to strengthen the admittedly weak connection with "Buffy the Vampire Slayer", since that series has many Lovecraft overtones.
- 2370: A graveyard on the Federation colony world of Caldos II contains a marker inscribed "McFly". From the Star Trek: The Next Generation episode "Sub Rosa". Given the manufactured Scottish culture present in the colony, it's not impossible that some descendants of the Irish-derived McFly family of Hill Valley might choose to settle there. And we already know that Marty's descendants take to the stars fairly early on . . .
* OK, I have a bit of gushing. I was seriously pleased that a couple of fairly obscure works I happen to be familiar with made it in - namely, the Gabriel Hunt book Hunt at the Well of Eternity (which obliquely mentions Indiana Jones) and the Burn Notice novel The Fix (which mentions Crockett and Tubbs of Miami Vice). What can I say, I enjoy this kind of thing.