Checking someones bandwidth and loading content based on it

Question

I have seen a number of questions that don\'t answer this, is it possible to check someones bandwidth using java script and load specific content based on it?

The BBC se

Answer 1

I've knocked this up based on timing image downloads (ref: http://www.ehow.com/how_5804819_detect-connection-speed-javascript.html)

Word of warning though:

It says my speed is 1.81Mbps,

But according to SpeedTest.Net my speeds are this:

The logic of timing the download seems right but not sure if it's accurate?