Here's the link to a tutorial at Ubuntu Geek. The easy-to-follow graphical presentation claims a 3x to 30x speed up in Firefox. What do you think?http://www.ubuntugeek.com/speed-up-firefox-web-browser.html
8 tweaks in all:
I tried them all in VL 5.8 Std, with no negative effect. I did not bother with supplemental tips at the end of the tutorial. Feedback to the above tutorial claims that FasterFox does all this out of the box.