Internet Speed Tests

[Johnny.Bravo]

Does anyone know why there is such a huge difference between data speed test results from Speedtest.net - The Global Broadband Speed Test and Speakeasy - Speed Test

Connected to the wifi in my house on Speedtest I get around 7Mbps download speed. But then I run it on Speakeasy and I get 18Mbps. According to my local cable company I have a 15Mbps internet connection, so as far as I am concerned they are both off. Any suggestions for a reliable data speed test site? Oh, BTW when I use the Speedtest app from the Market I get 3.5Mbps, so there's yet another different result.