i just done some of this and it seems to make fire fox faster (i didnt do number 1 coz couldnt find it but i did the rest)
First, Lets change some hidden options to make firefox faster...
Open Firefox and in the address bar type: about
:config
1.Find browser.tabs.showSingleWindowModePrefs and double click on it so it = true.
(This enables advanced tab options in options page.But this string may not be present in some versions of firefox)
2.Find network.http.pipelining & "network.http.proxy.pipelining" to "true" and double click on them so it = true
(This will enable pipelining which will be explained next)
3.Find network.http.pipelining.maxrequests double click on it and change it from 4 to 100 (16 to 32 will be optimum if it is above the sites may ban you thinking it's a DOS attack)
(This makes FF use 8 threads to each page.This due to pipelining)
4.right-click anywhere and select New-> Integer. In the alert box type"nglayout.initialpaint.delay"and set its value to "0". This value is the amount of time the browser waits before it acts on information it receives.
If you're using a broadband connection you'll load pages MUCH faster now!
this is where i found it
http://www.luckytips.co.nr/firefox
it dont make downloads faster it just makes pages open faster things like that