Actually yes it has, in a television series that was WAAAAY ahead of the curve and died in one or two seasons. It was called “Special Unit 2” and was about a group of Chicago cops whose job it was to deal with supernatural entities. The two lead cops had a gnome as an informant. One of the cases involved staking out a foul-mouthed fairy to catch a monster that dined on them.
It was a hugely fun, hugely funny series so of course it was cancelled in short order.
Modern conveniences. Is that a UK/Ireland term, then?
No, wasn’t commenting on the Mods of the board. This time. 
I think it’s more that technology was transparent or hidden. They did have clocks and pocketwatches, for instance (Bilbo has both, in The Hobbit, but such things seem to generally not be worthy of mention. It’s hard to say what other sorts of similar conveniences they may have had, somewhere in the background. And there were also secret technologies: Gandalf was renowned as a maker of fireworks, and his may have been partly magical, but he was not the only pyrotechnician in Middle Earth, so there must have been others using more prosaic means. And craftsmen in Gondor’s golden age were able to make things like the tower of Orthanc, which is impervious to tree roots. So I’d say they had plenty of technology
You make some fair points, but in the end I think Tolkien gave extreme short shrift to man’s main advantage in the real world (his aggressive intellect) WRT to the relative technological stagnation of people in LOTR. Including “pocketwatches”, but leaving out scienfitically co-terminous things like cannons and Man O’ Wars etc is more than bit “luddistic”. Granted, it’s a fantasy story, but in any halfway realtistic scenario of competition between men and the other races or “fell beasts”, men would have been kicking ass and taking names in short order in a few hundred years, not a few thousand.
Well, it’s pretty well implied that in the Fourth Age, the Age of Man, the future outcome for the unspoiled places in Middle-Earth was pretty dim. Aragorn was unusually enlightened by his decades of education and upbringing by the Elves, and I’m sure that his son would be similarly inclined with Arwen as his mother, but after that, without Elves to protect the natural world, the outlook was pessimistic at best.
And note that even during the events of the War of the Ring, Treebeard lamented the loss of the leagues and leagues of forest that used to stretch from the the west of Beleriand to where Mirkwood now stands.
The OP (and others) may be interested in reading the “Doc Sidhe” series of novels by Aaron Allston.
The first one is available online, gratis, at the Baen Free Library.
I give to you the huge money and time sucking monstrosity (but in a good way) that is Warhammer 40,000.
http://us.games-workshop.com/games/40K/default.htm
The ray gun shooting elves are called ‘Eldar’ and they actually shoot monomolecular disks at super high velocities… usually. I hate them.
They actually got rid of the space dwarves some years ago, but they WERE called ‘Squats’.
The hobbits are called ‘Ratlings’ and are skilled cooks and snipers. Not playable as a race on their own, only attached to Imperial Guard armies.
The superior race of men (Numenor-esque) are genetically enhanced Space Marines, of which there are many chapters including the Rohan like Space Wolves.
Humans worship a mummy kept in stasis as a God-Emperor and technology is like magic tended to by an elite priesthood… they can replicate stuff… repair it… but have really no clue as to how or why it works alot of the time. Oh, and they’re rabidly xenophobic much to the rest of the Universe’s delight.
The bad humans (as if the good humans weren’t bad enough) are demonically posessed mutant Space Marines that live to ruin just about everybody’s day. They are by far the most popular group of armies played right now, everybody loves a bad boy.
Then there are the pop culture add ons grafted onto this Tolkien/Herbert kludge which include the Tyranids which are not at all just like the monsters in the ‘Aliens’ movies, the Necrons which aren’t quite like Terminator/Undead/Borg robots from Hell and the Mecha/Anime inspired Tau which are the closest thing to a real “Good Guy” army in this entire Universe.
I myself play Tau and Spacewolves.
Would elves with submachine guns do?
John M Ford’s “Last Hot Time” is set on Earth after the return fo the elves. It’s been compared to the “Borderlands” series–which I haven’t read.
It’s an annoyingly slender book that leaves you wanting more. Good antidote to those endless “Tolkien ripoff” series of bulky volume after bulky volume.
Since we’ve gotten into the realm of games (although Shadowrun has novels for it and I’m pretty sure Warhammer does, too…), I’ll throw in the d20 Modern setting Urban Arcana - typical fantasy creatures have been crossing through ‘Shadow’ for thousands of years, and living among us - usually passing for Humans, since few Humans are willing to believe they exist, so they ignore the oddness - assuming it’s a race that can’t look EXACTLY like a Human.
There’s also Dragonstar which is a Space Opera with Dragons, Drow, Dwarves, Orcs, Elves, Gnomes, etc.
There was Dinosaucers.
Let us not forget The Terrible Thunderlizards either.