This is probably not really a ‘hot’ key. Probably more like a useful key or a useful tip. However it is surprising how many people are not aware of it.
The following works under Windows on a PC; I have no idea if this works for Linux or Mac computers.
When in a Web browser—such as Internet Explorer (IE), FireFox, or Opera—and you want to see the next screen of information you can simply tap the space bar. Hitting the space bar will cause the browser to scroll down a page; well a screen really.
This obviously assumes that the cursor is not positioned in an input zone when you tap the space bar—which will, as you might expect, simply enter a space into the input field.
If you are doing some lazy Web surfing, maybe laying in bed using a notebook computer, it will generally be much easier to lean over and tap the space bar than find the PageDown (PgDn) key and tap that, or line the mouse up on the vertical scroll bar and click it.
Finding the PageDown key on a notebook can be quite a challenge sometimes. Especially for people like me who work with a full standard keyboard 99.5 percent of the time. There are no standards with notebook keyboards about where the PageDown key is to be located. It could be anywhere to the right of centre on the keyboard. But the faithful old ‘space bar’ is always in the same place; and its big too so it is hard to miss—evening leaning over in bed.
If you are using the Opera browser then there is another trick that the space bar will do. When you get to the end of the scroll area if there are other pages to continue on to, and assuming the page has been formatted correctly (and most are these days), then Opera will automatically go to the next page for you when you tap the space bar. Seriously. I kid you not.
And, not quite as convenient, but worth knowing anyway, if you do Shift+Space bar then the browser will scroll up a screen (i.e., go backwards).
I just don’t know why I don’t get a lot more people visiting my site when I give away little gems of information like this *G*