How about chalk?
Take a chunk, and write on stuff. Not much there to be changed and/or modified across the ages.
The woven reed basket.
Followed closely by the woven reed sun hat.
Beer was enjoyed in Egypt, what, 3000 years ago? Wine’s even older. Do those count as “technology,” though?
Adam
Hey! Nobody’s said “clothing” yet, but you’re real close.
(Isn’t it kinda weird what all we’re referring to as “technology”? Somehow that term suggests moving parts, electricity and gears to me.)
See my reply to Bosda just above. Great minds? 
Here’s something that’s not so old, but remarkable none-the-less:
It was first produced in 1905, and was the standard-issue handgun in the combat arm of the United States Armed Forces from 1911 to 1985.
It’s still extremely popular today. And the design – despite being 100 years old – has remained virtually unchanged.
What about an abacus?
Is that old enough to count (ha!)?
Hence the sign they encountered in Egypt: “don’t drink fermented barley and wheel”.
I was going to mention various calendars, time pieces, counters, calculators, tally sticks, and so forth. The abacus is about as good an example as there is, and most unchanged of the ones I know of.
How about the concept of an idealized platform in space? Such as a chair, table, raised bed, etc.
Don’t forget the shovel and the wheelbarrow
I suppose it’s unfair to continue this topic without mentioning primitive weapons which have remained essentially unchanged over the millennia:
Spears
Bows and arrows
Slings
Boomerangs?
Deadfalls (and other basic traps)
and, at least if one has hilly country to play in, rolling boulders down hills to knock over stage coaches and Conestoga wagons.
I propose making this challenge a bit more stringent…
Name an item that is manufactured and sold in the US today, and one that is NOT specifically intended to be a museum replica/collector’s item/old thing model, which you could travel back in time, leave for someone in a past society to find, and they would not only know what it was and be able to use it, but would not be at all startled by its form, apperance, or materials.
Your best bet in that case might actually be some forms of art. There are probably artists working somewhere right now who are producing carved rock sculptures which, if found by neolithic people, would be recognized and accepted as rock sculptures.
If you’ll expand “some forms of art” to include those endeavors most usually referred to as “crafts” I’d suspect you could get more utilitarian objects in that category. I saw an episode of Odyssey back in the early 80’s that had some current day anthropologists using flint tools to kill, dress and make garments from bison. The results were very impressive. Gourd drinking vessels, pottery, beads, body ornaments, and other things not usually regarded as art per se, would fit your criteria, IMO.
Howsabout a mortar and pestle, or any of the other stone food-grinding implements (metate y mano, etc.)?
Chopsticks. Or the Fork.
Hammocks, pottery wheels, hinges, door latches, skeleton keys, candles, dice, earrings, rings, necklaces, wine, beer, chess pieces, bells, baskets, ceramic anything, woven anything, canoe oars?, pipes?, recorders, horse saddles, etc. horse shoes and i’m sure other leather goods.
things that are essentially the same but some materials have been refined: mirrors, scissors, stringed, brass and percussion instruments, looms, coins, stamps (as in to stamp in wax)
What about matches themselves? I’m sure they’ve changed in size/shape/color somewhat, but how old is the basic design?
I’d go with a spoon over a fork. It didn’t really become common in Europe as an eating utensil until after the sixteenth century, being seen as excessively dainty. (Cooking forks, i.e.: two-pronged sticks for poking, are different.) Spoons have been around since the Paleolithic era. The earliest one is from Egypt, I think.
Evidence of tablet weaving (also known as card weaving) have been found dating to 400 B.C. I think this is extraordinary, since I just can’t wrap my mind around how it works.
Braiding has been around for a long time, too. I believe that Otzi the Iceman had braided textiles with him, though woven socks were discovered dating from the same period as Otzi (though in a different place), so braiding has to date waaaaay before 5000 years ago.
The Zippo Lighter was invented in 1932 and has remained virtually unchanged and wildly popular ever since. Now THAT is a great invention!