The Jawbone box is such one.
They've a small and a bigger one, I have the small one.
It's 15x4 cm, height 5,6 cm (inch: 5,9x1,6 and height 2,2).
Say two cigaret packages, but thicker.
See pictures below.
You can accept Incoming calls by pressing a button, and talk back through the built-in mike.
The battery goes for 10 hours, a voice tells you when it's time to load.
There are more usefull messages, and you can choose your favorite voice from the website.
The music playing software (special filters for different volume levels etc.) can be updated with whatever. Like for the spacializer effect so far.
Pressing all buttons at once activates a short audio demo, with a surprising-extreme stereo effect at the end.
The metal housing is robust, it has some pleasant weight, the plastic part of the housing has that nice 'not slippery' touch which some consumer cameras have, like HP.
The metal/plastic box comes in black, blue and red, mine is the small one and is black, it has the metal cover print of the big one (see picture).
A suede cover with smart folding design is for the good feeling, important with a price of about 160 euro.
You can have it for about 125,- euro I guess.
Ok, nice, it might do more and has a few plusses more than other boxes have, what's further so special about this one, except the price?
You guys know me as quite sober, in arguements that is

Well, the sound is s-t-u-n-n-i-n-g


Absolutely amazing.
It's exactly like the slogan from Jawbone says: your eyes won't believe your ears, and I didn't know that slogan yet when a friend of mine showed me his Jawbone box.
I have the box already for 3/4 year now, it was a must have for my bus T3 holidays

But those faces of friends when we showed it to them...they couldn't believe, every time again.
Put it upside wise on the table in the middle of a big conversing group, and it's all you need concerning the music, even at half volumes.
The basses are huge and beasty, and the overal sound picture is really in great balance: not the least of the phone speaker effect, even not after a longer time of listening. On the contrary even, it's a joy with every new track played

The spacializer is fantastic, the sound fills your complete room, yet without any artefacts like squint making out-of-phase effects.
Loud, bright, bassy, fat, but your neighbours won't notice

If you lay the box with it's bottom on your brest sitting in a lousy chair, you have a real sensation of the pushing effect of a fat PA.
I believe it are not speakers but kinda powermembranes at the backside.
You feel every kick stomping on your chest, even at low volume at night in your garden.
If you put the box on a table or on a plasic or carbon box it really does something with the surface.
The back side gives less highs than the front speakers, but the special membranes are what makes the Jawbone what it is:
by far the best sounding box in the world, as far as I know, and as far as Jawbone claims.
It seems the electronica of the jawbone is hard to copy as it's covered in molded resin.
There's also specific audio software invloved, according to Jawbone (firm).
Megastore Action i.e. has a good looking copy for 30,- euro, but the sound is terrible, I heard one.
It's a lot of mony, you can have it for about 125,- euro, that's already a lot in my country, let alone in some other countries.
But if you have a box in mind, you are obliged to yourself to check this one out, at least to know what's possible.
It's not worth it for children, but it's a serious soundsystem for intimate listening situations.

Jawbone is California based, here their own presentation:
For more than a decade, Jawbone has developed human-centered wearable technology and audio devices unparalleled in their technical innovation, ease-of-use and sophistication of design. A 2010 IDSA Design of the Decade winner, the company is the creator of the award-winning and best-selling Jawbone ERA and ICON Bluetooth® headsets; NoiseAssassin® technology, the world's first and only military-grade noise-eliminating technology; and the JAMBOX wireless speaker and speakerphone. Jawbone is privately held and headquartered in San Francisco.