You have to be a registered member to use these speed tests. 

On the left menu you will find a selection of speed test sites.  (Register to see links)

Make sure you test your adsl connection during off-peak and peak times to see if your ISP is throttling your connection or over subscribing.

Speedtest.net

This is the one I like most. It seems pretty accurate and looks best.  It shows you your download and upload speeds along with your ping to different servers around the world.

BT Speed Test

If you want to know if your ip profile is stuck then this is the test for you.  It shows what BT have your ip profile set at, your sycn speed to the modem and your actual throughput speed.

ThinkBroadband

This test tells you your download and upload but before showing you the results asks you to name and rate your ISP(internet service provider)

_________________________________________________

After checking your adsl speed on these tests you might be thinking of changing your ISP.  

If you do take a look on this ISP rating website and see who's top in the ISP charts.

                      DSL ZONE ISP RATINGS