I've just spent a few minutes playing around with fivesecondtest. It's a bit addictive. It's an online tool for usability testing. From the site:
People use five second test to locate calls to action, optimize landing pages, and run A/B tests. You can use them for whatever you like.

You can either submit content for testing, or you can be a tester. There are two test scenarios: five second memory test and five second click test. With the memory test, you see an image for five seconds and then you're asked to list five things you remember. With the click test, you're asked to click on things you notice in five seconds, then describe what they are.

The memory test is hard. Five seconds is a lot of time, and I noticed the following patterns with my testing:

  • The more text a site had, the less I remembered

  • The more detailed the graphics the site had, the less I remembered

  • The larger the images, the less I remembered

  • The more correlated the logo and site look and feel were to the product, the more I remembered

  • The less fancy the font, the more I remembered

  • The fewer headings the site had, the more I remembered

The click test was much easier, and for me, more fun. I noticed the following:

  • I clicked on contact information when it was there

  • I clicked on headings when they were there

  • I clicked on social media links when they were there

  • I clicked on forms (submit a question, etc...) when they were there

  • I clicked on user ratings when they were there

I like the idea of using something like this to gauge if a call to action is effective. I also suspect it can help you easily determine if your site might be too busy. I know I froze up on the more complex sites. I both couldn't remember anything and I couldn't focus on anything long enough to click on it before time expired. It became apparent to me what types of designs "worked" for me.

If you need some simple usability feedback, give it a try. If you're a tester and just want something fun to practice on, I found this a nice short diversion. I suspect I'll check back from time to time to test other designs.