I have noticed the whole time that browsing seems to be slow. I came across this post (http://www.ubuntuforums.org/showthread.php?t=202838) and consequently changed the firefox config file resulting in a very noticeable speed-up in browsing!
In the firefox navigation bar, type: about:config
Then change this setting:
network.dns.disableIPv6 user set boolean true
Note: this disables IPv6, but in future, when IPv6 gets used more/accepted by ISP, this setting should be changed back.