Few tips for Firefox:

Disable referer logging (enhances privacy):
In URL field type about:config enter network.http.sendrefererheader into Filter field and change the value of only entry there.

0 - Remove all referers (recommended)
1 - Remove referer only for images
2 - Referer enabled

Enable Pipelining (browsing speed boost):
In URL field type about:config enter network.http.pipelining into Filter field and change the value of first entry there.

For network.http.pipelining:
True - Enables pipelining
False - Disables pipelining

For network.http.pipelining.maxrequests:
4 is default,higher means better performance,but only on extremely fast lines (8Mbit DSL or T1/T3). Setting too high might reflect in worse speed.
I recommend that you leave number 4.
Also note that not all webpages support pipelining.