MMO-Gaming.com is my other site.
It uses a service provided by someone else, what it does is actully downloads something to your computer (completly safe) and tests how fast it could do it and the uploads the same thing and tests that speed.
In my opinion it is not Accurate but verry near because you could be in Austraila and the service in England therefore not giving you the correct speeds for your area or country but its a good estimate.
Personally if your not happy with that one there is the
www.speedtest.net which has a selection of places to test against. So if your in England you can choose somewhere in England to do the test from.
Hope this helps
