"Bottleneck guitar", "slide guitar"
A blues thing, and also a rock and roll thing. "Bottleneck" is method of playing guitar with a tube of glass or metal (called a "slide") on one of the fingers of the fretting hand. You can play notes by holding the slide against the strings in one spot, and you can also slide the tube up and down the strings from one note to the next. I don't know if you'd call the result a glissando or portamento or what-all, but it sounds cool as hell if you know what you're doing (full disclosure: It's hard to do well, and I'm lousy at it). Some players put the slide on their little finger so they can hold it out of the way and play with the other three fingers; this is difficult. Most will leave at least one finger behind the slide so as to be able to mute the strings behind it.
If the strings are too close to the frets, it's a touchy business not to push the strings against the frets; you get undesired noises when you do that. Those who are serious about bottleneck playing, and who can afford it, will often keep one or more guitars around specifically for that purpose with the strings set very high off the neck. Since you don't have to wrestle the strings down to the fretboard, you can use very heavy strings, too. This is good: Heavy strings sound better and stay in tune better. They're hard on the neck, but guitars are mortal, and nobody's crazy enough to try it with a Rickenbacker anyhow. High action and heavy strings will make it impossible to get any goodness out of the above-mentioned trick with the slide on the little finger.
Bottleneck playing is at times done with "concert tuning" (E A D G B E, low to high), especially by those who have only one guitar, but that's very limited because that tuning is designed on the assumption that you can finger more than one fret at a time. It's not practical to do that with a slide: With a slide, wherever you are on the neck, there are only six notes you can get to in a real hurry1: Therefore, it's a good idea to use a tuning which will ensure that all six of those notes are likely to be useful, especially in combination with each other. "Open tunings" such as open G do the job reasonably well.
The name "bottleneck" comes from the fact that the earliest slides (in the Mississippi Delta, IIRC) were made by sawing off the necks of bottles and filing down the sharp edges. Nowadays you can walk into a music store and buy one for five bucks; this is less picturesque but more convenient. Howe Gelb of Giant Sand has been known to play "bottleneck" with an entire beer bottle, with beer still inside (at first). He is a man who understands efficiency and convenience. I recall reading about Bob Dylan using a butter knife and a lipstick tube to the same end in the studio while recording some of his early albums.
Ry Cooder is well-known for playing bottleneck, the late Duane Allman made a career of it, Robbie Krieger dabbled in it (e.g. "Moonlight Ride"), and Bonnie Raitt is good; she's the best bottleneck player I'm aware of right now (mind you, my awareness has stark and harrowing limits). Dave Roback of Mazzy Star plays bottleneck often; if you remember their one quasi-hit, "Fade into You", that floaty, drooping high guitar line was done with a slide.
I've utterly failed to mention any originators. My knowledge of the blues is shockingly inadequate, and ordinary research just won't cut it; this node would benefit enormously from a writeup by somebody who actually knows something about the subject. Like, I think Robert Johnson played bottleneck, but I'm not certain and I just don't know the guy's music at all well.
Related phenomena include lap steel and pedal steel "guitars"; they are way cool, but they are mutants, hardly guitars at all.
1 ...unless you pop the slide up and use open strings, which is limited for obvious reasons. Holding the slide at an angle across the fretboard is a neat trick if you can manage it with accurate intonation. Good luck. That'll be increasingly difficult as you get down among wider frets nearer the nut, where you'll need a steeper and steeper angle to get to the next fret. When you think about it, it's just not going to buy you all that much very often.