Is there any good website for measuring IQ?

Is there any good website for measuring IQ? I understand it is very broad and vary depends on many factors. I am looking to measure IQs for a group of people, say employees of a startup on a regular basis for fun and other actions.

Some sites like http://www.iqtest.com/ only have static set of questions. Looking something with decent dynamic questions. Basically looking something like Brainbench for IQ testing.

Thanks.