mixx is a new service like digg. mixx is not popular on the Internet so far.
But, it will be popular in the near future because a button to mixx is now placed on CNN.com. Each news article has a little red mixx button. When you want to mixx the news, just click the button and you are navigated to the page to add it on YourMixx. It's very easy.　Just try mixx.(www.mixx.com)

Now mixx doesn't have an iGoogle gadget yet, so I hope someone makes the gadget as early as possible.