** In the book it's mentioned that for all the technology the Martians never seem to have invented something as simple as the wheel, what are the Martians so fascinated by when we see them outside their tripods? A bicycle wheel.
** Why does the Martian's weapon (in one of the movies) leave clothing intact? Its an highly-focused ''enhanced radiation weapon'' similar to a neutron bomb, which is designed to wipe out enemies soldiers but leave their infrastructure relatively intact. This is why it dessicates humans into ash but less of an effect on clothing (and armour). Similarly, it also demonstrates similarlities to a neutron bomb's having some concussive force, in the way that it impacts objects. It isn't a "heat ray" at all, as throughout the films, we never see it ''ignite'' objects, the only fires seen are clearly caused by explosions from other sources.
** When the aliens go through Ogilvy's basement, they all look at a picture of what's presumed to be Ogilvy's deceased daughter. Notice that they all look at it the wrong way (as in, never viewing it upright). Common from something that's never seen a photograph before.
** A lot of people complain about the ending -- where the Martians die suddenly of diseases resulting from Earth's bacteria that they are no longer immune to -- as being a DeusExMachina that comes out of nowhere to solve the plot. Read the first chapter again. Literally the first paragraph of the book -- and every adaptation which draws on it -- compares the way the Martians look at humanity to the way humans look at bacteria; dispassionately, as something small, insignificant, easily dismissed or forgotten about. And yet any expert will tell you that in the right conditions bacteria can be devastating. The ending was hinted at right from the beginning... and if you forgot about it, you made the exact same mistake the Martians made.
** The aliens somehow get gigantic war-vehicles to come out of the ground. See the JustBugsMe page for more in-depth discussion.