First off I want to let you know that I am the creator and owner of testmyiphone.com and I'm going to answer a few of these concerns that some of you seem to have.
First off the problem where the test would not take you to the results page has been fixed, as far as we can tell, I changed a few things this morning and I have not had the problem at all since I made the changes this morning, so I'm pretty sure that problem has been fixed.
The problem ivtecDOu had a few posts up where gave him a wifi like result even though he is connected on edge. This is caused by the unique key that we use for each test. When a speedtest is taken it is given a 12 digit key to identify the test, some times what happens is that key is already in use so when you are taken too the results it pull the results from the first test with that key. We are working on a fix for this, and it will be up real soon. This does not happen often though, only about once for every 1000 tests taken. Its just really annoying when it does happen and I will fix it.
sanPietro98 asked how accurate are these speedtest sites. I can say that they can be very accurate. But sadly most aren't that great, and give inaccurate results because the testing method they use is quite bad. For example any speedtest site that uses a image to test the speed of your connection will always be inaccurate for 2 reasons. 1. The test file size stays the same, no matter if your connection is 512kbps, or 10mbps. and 2. Images can and do get cached by the browser so the second time you run the test you could be pulling the image used from the cache of the browser not from the sites server.
Our speedtest works in the same way a desktop level speedtest does, but is designed to be light weight for the iphone. It is very similar to the way the testmy.net speedtest works to be able to give the user a 6 - 8 second speedtest.
Every time you take a speedtest at testmyiphone.com it does a small 256kb test, then we do some stuff to determine the larger test that needs to be run so you can get a accurate test up to a max file size of 10mb. By doing this we can give you the most accurate results, of any iphone speedtest.
Our speedtest server is located in Montreal Canada, we will be moving to server in Dallas, Tx very soon. Once we do that users on the west coast will have much more consistent results, and users in other countries will also see better results as we will have better international carriers.