If you have a fast connection, this is for you:
1. Type: about:config
2. Set:
network.http.max-connections : 96
network.http.max-connections-per-server : 32
network.http.max-persistent-connections-per-proxy : 24
network.http.max-persistent-connections-per-server: 12
network.http.pipelining : true
network.http.pipelining.maxrequests : 8
network.http.proxy.pipelining : true
network.http.keep-alive.timeout : 30
network.ftp.idleConnectionTimeout : 60
nglayout.initialpaint.delay : 0
content.notify.ontimer : true
content.notify.interval : 100
content.switch.threshold : 100000
content.notify.backoffcount : 200
content.max.tokenizing.time : 3000000
browser.xul.error_pages.enabled :true
general.smoothScroll: false
browser.cache.disk.capacity : 76800
config.trim_on_minimize : false
You should now open pages a lot faster ;)