No big things like Phasers, Pulse Pistols, Holodecks, Warp Drives/etc…, what little things would you love to see realized from sci-fi…
the Babel Fish
Translator Microbes
the “Lightsaber” bread knife from the HHGTTG movie (toasts bread while slicing it…and makes cool “lightsabery” noises)
i’m sure i’ll think of more as i go, what minor devices would you like to see realized?
These are little? a Universal Translator is little? (Even if you’re talking about size, rather than impact, a Babel Fish is a multidimensional creature.)
Ansible (FTL communication, from LeGuin and then others)
Light Pump from Sturgeon’as “Microcosmic God”
Slow Glass (from Bob Shaw’s stories. Not only good for storing light, it ought to make a helluva bomb)
Variable Sword (from Larry Niven’s “known Space” series – closest thing in SF to a Light Saber)
Nerd (from Jack Chalker’s “Web of the Chozen”. The Petri Dish full of Agar of the future)
The transporter. That one thing would really make a difference.
Heck, the toaster in Fahrenheit 451 that butters the toast automatically would be pretty sweet.
…long unused synapses firing…
I remember that! I assume that he used it more than once. Off the top of your head, do you remember the stories in which it was mentioned? Here’s his bibliography if you need it. Nothing rang a bell with me, but I know I’ve read a story with slow glass in it.
The three seashells. 
Might help if I did a quick Google… :smack:
…and I finds the whole darn story!
A stasis field.
from Red Dwarf
Talkie Toaster
scutters
Better Than Life
from Star Trek
the tricorder – you could take it to a bar, and scan it up and down in front of the hot babe you want to pick up. Say something like, “Captain, the readings are off the chart. I need to get this specimen to bed for further analysis!” (Of course, then you’d need a dermal regenerator to repair the gouges she claws into your face…)
Any type of wireless communicator used in any sci-fi story anywhere. I’ve not once read a story where any character suffers from dropped calls. 
Tomasite plastic, from the old Tom Swift Jr. novels.
It was as transparent as glass, but heatproof, & an amazingly effective radiation shield. Lightweight, too.
I want a replicator. And a Replicator Jr. for the office.
A sonic screwdriver. Dr Who could do anything with that.
Could I just vote for Rosie the Robot. I would settle for Kryton, but I think Rosie was a more competant model.
While I’m at it, does George Jetson’s car count as minor?
The nine billion names of God.
I don’t know how they work, but it’s got to better than the “pushing peanut butter through a shag carpet with a cotton ball” method we have now.
Going a step further, a medical tricorder. No need to ever go to a doc for a checkup!
In the SW prequels the Jedi would whip out these little mini-SCUBA thingies when they needed to travel some distance underwater without an enclosed vehicle. I could have a lot of fun with one of those. Imagine being able to dive off some reef in the Carribean and need no gear but this little mouthpiece you can stick in your pocket. I’d buy that for a dollar for sure.
The holodeck, baby, heheheh…yeah!
I second the replicator. All you’d need is one. Theoretically, you could repiicate more replicators (or at least the parts to make them), until everybody had one. And then no one would lack for food or clothes or basic medicine ever again, as long as they had some spare base matter on hand. I second the tricorder as well. I seem to remember hearing something about a company designing a real life version of one, if anyone could find a cite on that I’d be most appreciative.
Also, I maintain that a hand phaser is small enough to fit the OP’s requirements.