Cultural reference

Numerous easter eggs are one of the staples of the Fallout series. These are instances where something or someone from pop culture or the real world is referenced in the game itself, e.g. Fallout 2 has an encounter with King Arthur.

The Goonies
Reference to the movie "The Goonies" When you go down into the well in the center of town in Modoc, you'll see several bags of coins lying around. If you pick one up, then your character will say a line almost identical to the line spoken by "Mouth" (played by Corey Feldman) in The Goonies when he and his friends find themselves at the bottom of a wishing well.

Spotted by Jake Buroker

Bethesda
There are ruins of Bethesda's office buildings overrun by Raiders. Bethesda Softworks is the company that made Fallout 3. However, this is easily explained, as the company is located in Bethesda, MD, a suburb of Washington, DC.

Occam's Razor
One of the melee weapons called "Occam's Razor" is reference to the theory of William Ockham. His theory called Occam's Razor, boils down to "All other things being equal, the simplest solution is the best." In other words, when multiple competing theories are equal in other respects, the principle recommends selecting the theory that introduces the fewest assumptions and postulates the fewest entities. It is in this sense that Occam's razor is usually understood.

Spotted By: ZomB

Farragut
One of the settlements is Farragut West, which is reference to a station on Washington DC's metro system. It is also the name of NPC Lucien Lachance's Hideout in Oblivion (Fort Farragut).

Raven Rock
It's also a mining village back in The Elder Scrolls: Morrowind, the Bloodmoon expansion. However, it is likely a coincidence, since the Raven Rock Mountain Complex is a real-world government complex.

Dogmeat
A homage to Fallout 1 & 2, Dogmeat is named after a similar NPC canine character in both games. You can choose to rescue him or not. Dogmeat can be sent to scavenge for food or items, but you must be cautious, as he cannot be revived if killed.

Mr. Burke
William Burke references a serial killer who killed at least 15 people in Scotland in the 1820's

Lunchboxes
These Lunchboxes are actually available from the Collector's and Survival editions of the game, and can be made into an explosive. It isn't recommended that you turn your Lunchbox into an explosive in reality - that would be illegal in most countries and a waste of a perfectly good Collector's item.