I've just slightly modified my Firefox about:config. After doing some research, I have changed the value of nglayout.initialpaint.delay from 0 to, wait for it, 1000000. Let me explain further.
If you use Firefox, chances are you know about about:config. If you don't, simply type it into the address and press enter or click on "go". about:config contains a few hundred lines of small tweaks you can make to Firefox. Of course, changing them willy-nilly may ruin your browsing experience so make sure you do the research first before changing any of the values.
nglayout.initialpaint.delay controls the time the browser takes between receiving the webpage information and its choice to actually show the page in the browser window. If it's set at zero, or some other small amount (I think the default is 250 - the number refers to milliseconds I think), then Firefox will begin to show the page while the information is still being downloaded. You know what this means... it means that you can view the webpage, but pictures and other things are still appearing as you look.
By changing to value to an absurdly high amount (in this case, I have changed it to 1000000), it essentially means that I have told Firefox not to bother trying to show the page until all the information has been downloaded.
In practice, this means that when I go to a website, the screen remains unchanged (if I have gone from one page to another) or is blank (if I have opened a new tab) until the entire page is ready to be viewed. Large web pages (like the Washington Post) can take over a minute to view, while smaller ones with hardly any graphics and information (like Google) take only a couple of seconds.
Of course, if you have viewed the page before, then the amount of waiting time is shorter, since a lot of information is kept in the cache.
Why do this? I have an obsolete processor (Pentium 3 600E) but a relatively large amount of memory (384mb). When nglayout.initialpaint.delay was set at zero, my poor processor strained so hard to cope you could hear the cries of dying slaves coming out of the box - which meant that while I was waiting to view a webpage, everything else I was doing had slowed down a bit. Setting it at 1000000 means that about 25% less processor power is used while, at the same time, all the information gets sent into my ample RAM to wait until it is needed.
I'm not sure whether this will actually enhance my browsing experience, but I'm testing it as I go. So far the only drawback is when I open 5 or more websites simultaneously in tabs - it can take a long time to actually view them all.